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Polito V, Liknaitzky P. Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research. J Psychopharmacol 2024; 38:701-711. [PMID: 38877715 PMCID: PMC11311906 DOI: 10.1177/02698811241254831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
Some recent research and commentary have suggested that most or all the effects reported by people who microdose psychedelics may be explained by expectations or placebo effects. In this rapid review, we aimed to evaluate the strength of evidence for a placebo explanation of the reported effects of microdosing. We conducted a PubMed search for all studies investigating psychedelic microdosing with controlled doses and a placebo comparator. We identified 19 placebo-controlled microdosing studies and summarised all positive and null findings across this literature. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomised trials. The reviewed papers indicated that microdosing with LSD and psilocybin leads to changes in neurobiology, physiology, subjective experience, affect, and cognition relative to placebo. We evaluate methodological gaps and challenges in microdosing research and suggest eight reasons why current claims that microdosing is predominately a placebo are premature and possibly wrong: (1) there have been only a small number of controlled studies; (2) studies have had small sample sizes; (3) there is evidence of dose-dependent effects; (4) studies have only investigated the effects of a small number of doses; (5) the doses investigated may have been too small; (6) studies have looked only at non-clinical populations; (7) studies so far have been susceptible to selection bias; and (8) the measured impact of expectancy is small. Considering the available evidence, we conclude that it is not yet possible to determine whether microdosing is a placebo.
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Affiliation(s)
- Vince Polito
- School of Psychological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Paul Liknaitzky
- Department of Psychiatry, School of Clinical Sciences, Monash University, Clayton, VIC, Australia
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Australia
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2
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Hutten NRPW, Quaedflieg CWEM, Mason NL, Theunissen EL, Liechti ME, Duthaler U, Kuypers KPC, Bonnelle V, Feilding A, Ramaekers JG. Inter-individual variability in neural response to low doses of LSD. Transl Psychiatry 2024; 14:288. [PMID: 39009578 PMCID: PMC11251148 DOI: 10.1038/s41398-024-03013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 06/21/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024] Open
Abstract
The repeated use of small doses of psychedelics (also referred to as "microdosing") to facilitate benefits in mental health, cognition, and mood is a trending practice. Placebo-controlled studies however have largely failed to demonstrate strong benefits, possibly because of large inter-individual response variability. The current study tested the hypothesis that effects of low doses of LSD on arousal, attention and memory depend on an individual's cognitive state at baseline. Healthy participants (N = 53) were randomly assigned to receive repeated doses of LSD (15 mcg) or placebo on 4 occasions divided over 2 weeks. Each treatment condition also consisted of a baseline and a 1-week follow-up visit. Neurophysiological measures of arousal (resting state EEG), pre-attentive processing (auditory oddball task), and perceptual learning and memory (visual long-term potentiation (LTP) paradigm) were assessed at baseline, dosing session 1 and 4, and follow-up. LSD produced stimulatory effects as reflected by a reduction in resting state EEG delta, theta, and alpha power, and enhanced pre-attentive processing during the acute dosing sessions. LSD also blunted the induction of LTP on dosing session 4. Stimulatory effects of LSD were strongest in individuals with low arousal and attention at baseline, while inhibitory effects were strongest in high memory performers at baseline. Decrements in delta EEG power and enhanced pre-attentive processing in the LSD treatment condition were still present during the 1-week follow-up. The current study demonstrates across three cognitive domains, that acute responses to low doses of LSD depend on the baseline state and provides some support for LSD induced neuroadaptations that sustain beyond treatment.
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Affiliation(s)
- Nadia R P W Hutten
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Conny W E M Quaedflieg
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Natasha L Mason
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Eef L Theunissen
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Matthias E Liechti
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Urs Duthaler
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Kim P C Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | | | | | - Johannes G Ramaekers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands.
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Basedow LA, Majić T, Hafiz NJ, Algharably EAE, Kreutz R, Riemer TG. Cognitive functioning associated with acute and subacute effects of classic psychedelics and MDMA - a systematic review and meta-analysis. Sci Rep 2024; 14:14782. [PMID: 38926480 PMCID: PMC11208433 DOI: 10.1038/s41598-024-65391-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 06/19/2024] [Indexed: 06/28/2024] Open
Abstract
Classic psychedelics and MDMA have a colorful history of recreational use, and both have recently been re-evaluated as tools for the treatment of psychiatric disorders. Several studies have been carried out to assess potential long-term effects of a regular use on cognition, delivering distinct results for psychedelics and MDMA. However, to date knowledge is scarce on cognitive performance during acute effects of those substances. In this systematic review and meta-analysis, we investigate how cognitive functioning is affected by psychedelics and MDMA during the acute drug effects and the sub-acute ("afterglow") window. Our quantitative analyses suggest that acute cognitive performance is differentially affected by psychedelics when compared to MDMA: psychedelics impair attention and executive function, whereas MDMA primarily affects memory, leaving executive functions and attention unaffected. Our qualitative analyses reveal that executive functioning and creativity may be increased during a window of at least 24 h after the acute effects of psychedelics have subsided, whereas no such results have been observed for MDMA. Our findings may contribute to inform recommendations on harm reduction for recreational settings and to help fostering differential approaches for the use of psychedelics and MDMA within a therapeutic framework.
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Affiliation(s)
- Lukas A Basedow
- Department of Psychology, Clinical Psychology and Psychotherapy, Philipps-Universität Marburg, Gutenbergstraße 18, 35037, Marburg, Germany.
| | - Tomislav Majić
- Psychedelic Substances Research Group, Department of Psychiatry and Neurosciences, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Department of Psychiatry und Neurosciences, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nicklas Jakob Hafiz
- Institute for Educational Quality Improvement (IQB), Humboldt-Universität zu Berlin, Berlin, Germany
| | - Engi A E Algharably
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Charité Campus Mitte, Charitéplatz 1, 10117, Berlin, Germany
| | - Reinhold Kreutz
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Charité Campus Mitte, Charitéplatz 1, 10117, Berlin, Germany
| | - Thomas G Riemer
- Psychedelic Substances Research Group, Department of Psychiatry and Neurosciences, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Clinical Pharmacology and Toxicology, Charité Campus Mitte, Charitéplatz 1, 10117, Berlin, Germany
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Murray CH, Frohlich J, Haggarty CJ, Tare I, Lee R, de Wit H. Neural complexity is increased after low doses of LSD, but not moderate to high doses of oral THC or methamphetamine. Neuropsychopharmacology 2024; 49:1120-1128. [PMID: 38287172 PMCID: PMC11109226 DOI: 10.1038/s41386-024-01809-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/07/2024] [Accepted: 01/17/2024] [Indexed: 01/31/2024]
Abstract
Neural complexity correlates with one's level of consciousness. During coma, anesthesia, and sleep, complexity is reduced. During altered states, including after lysergic acid diethylamide (LSD), complexity is increased. In the present analysis, we examined whether low doses of LSD (13 and 26 µg) were sufficient to increase neural complexity in the absence of altered states of consciousness. In addition, neural complexity was assessed after doses of two other drugs that significantly altered consciousness and mood: delta-9-tetrahydrocannabinol (THC; 7.5 and 15 mg) and methamphetamine (MA; 10 and 20 mg). In three separate studies (N = 73; 21, LSD; 23, THC; 29, MA), healthy volunteers received placebo or drug in a within-subjects design over three laboratory visits. During anticipated peak drug effects, resting state electroencephalography (EEG) recorded Limpel-Ziv complexity and spectral power. LSD, but not THC or MA, dose-dependently increased neural complexity. LSD also reduced delta and theta power. THC reduced, and MA increased, alpha power, primarily in frontal regions. Neural complexity was not associated with any subjective drug effect; however, LSD-induced reductions in delta and theta were associated with elation, and THC-induced reductions in alpha were associated with altered states. These data inform relationships between neural complexity, spectral power, and subjective states, demonstrating that increased neural complexity is not necessary or sufficient for altered states of consciousness. Future studies should address whether greater complexity after low doses of LSD is related to cognitive, behavioral, or therapeutic outcomes, and further examine the role of alpha desynchronization in mediating altered states of consciousness.
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Affiliation(s)
- Conor H Murray
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
- Department of Psychiatry and Biobehavioral Sciences, University of Los Angeles, California, 760 Westwood Plaza, Los Angeles, CA, 90024, USA.
| | - Joel Frohlich
- Institute for Neuromodulation and Neurotechnology, University of Tübingen, Otfried-Müller-Straße 45, 72076, Tübingen, Germany
- Institute for Advanced Consciousness Studies, Santa Monica, California; 2811 Wilshire Blvd # 510, Santa Monica, CA, 90403, USA
| | - Connor J Haggarty
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Ilaria Tare
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
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Schmid Y, Bershad AK. Altered States and Social Bonds: Effects of MDMA and Serotonergic Psychedelics on Social Behavior as a Mechanism Underlying Substance-Assisted Therapy. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:490-499. [PMID: 38341085 DOI: 10.1016/j.bpsc.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/14/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
There has been renewed interest in the use of 3,4-methylenedioxy-methamphetamine (MDMA) and serotonergic psychedelics in the treatment of multiple psychiatric disorders. Many of these compounds are known to produce prosocial effects, but how these effects relate to therapeutic efficacy and the extent to which prosocial effects are unique to a particular drug class is unknown. In this article, we present a narrative overview and compare evidence for the prosocial effects of MDMA and serotonergic psychedelics to elucidate shared mechanisms that may underlie the therapeutic process. We discuss 4 categories of prosocial effects: altered self-image, responses to social reward, responses to negative social input, and social neuroplasticity. While both categories of drugs alter self-perception, MDMA may do so in a way that is less related to the experience of mystical-type states than serotonergic psychedelics. In the case of social reward, evidence supports the ability of MDMA to enhance responses and suggests that serotonergic psychedelics may also do so, but more research is needed in this area. Both drug classes consistently dampen reactivity to negative social stimuli. Finally, preclinical evidence supports the ability of both drug classes to induce social neuroplasticity, promoting adaptive rewiring of neural circuits, which may be helpful in trauma processing. While both MDMA and serotonergic psychedelics produce prosocial effects, they differ in the mechanisms through which they do this. These differences affect the types of psychosocial interventions that may work best with each compound.
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Affiliation(s)
- Yasmin Schmid
- Clinical Pharmacology and Toxicology, Department of Biomedicine and Department of Clinical Research, University Hospital Basel and University of Basel, Switzerland; Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Anya K Bershad
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, California.
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Metaxa AM, Clarke M. Efficacy of psilocybin for treating symptoms of depression: systematic review and meta-analysis. BMJ 2024; 385:e078084. [PMID: 38692686 PMCID: PMC11062320 DOI: 10.1136/bmj-2023-078084] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/06/2024] [Indexed: 05/03/2024]
Abstract
OBJECTIVE To determine the efficacy of psilocybin as an antidepressant compared with placebo or non-psychoactive drugs. DESIGN Systematic review and meta-analysis. DATA SOURCES Five electronic databases of published literature (Cochrane Central Register of Controlled Trials, Medline, Embase, Science Citation Index and Conference Proceedings Citation Index, and PsycInfo) and four databases of unpublished and international literature (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, ProQuest Dissertations and Theses Global, and PsycEXTRA), and handsearching of reference lists, conference proceedings, and abstracts. DATA SYNTHESIS AND STUDY QUALITY Information on potential treatment effect moderators was extracted, including depression type (primary or secondary), previous use of psychedelics, psilocybin dosage, type of outcome measure (clinician rated or self-reported), and personal characteristics (eg, age, sex). Data were synthesised using a random effects meta-analysis model, and observed heterogeneity and the effect of covariates were investigated with subgroup analyses and metaregression. Hedges' g was used as a measure of treatment effect size, to account for small sample effects and substantial differences between the included studies' sample sizes. Study quality was appraised using Cochrane's Risk of Bias 2 tool, and the quality of the aggregated evidence was evaluated using GRADE guidelines. ELIGIBILITY CRITERIA Randomised trials in which psilocybin was administered as a standalone treatment for adults with clinically significant symptoms of depression and change in symptoms was measured using a validated clinician rated or self-report scale. Studies with directive psychotherapy were included if the psychotherapeutic component was present in both experimental and control conditions. Participants with depression regardless of comorbidities (eg, cancer) were eligible. RESULTS Meta-analysis on 436 participants (228 female participants), average age 36-60 years, from seven of the nine included studies showed a significant benefit of psilocybin (Hedges' g=1.64, 95% confidence interval (CI) 0.55 to 2.73, P<0.001) on change in depression scores compared with comparator treatment. Subgroup analyses and metaregressions indicated that having secondary depression (Hedges' g=3.25, 95% CI 0.97 to 5.53), being assessed with self-report depression scales such as the Beck depression inventory (3.25, 0.97 to 5.53), and older age and previous use of psychedelics (metaregression coefficient 0.16, 95% CI 0.08 to 0.24 and 4.2, 1.5 to 6.9, respectively) were correlated with greater improvements in symptoms. All studies had a low risk of bias, but the change from baseline metric was associated with high heterogeneity and a statistically significant risk of small study bias, resulting in a low certainty of evidence rating. CONCLUSION Treatment effects of psilocybin were significantly larger among patients with secondary depression, when self-report scales were used to measure symptoms of depression, and when participants had previously used psychedelics. Further research is thus required to delineate the influence of expectancy effects, moderating factors, and treatment delivery on the efficacy of psilocybin as an antidepressant. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42023388065.
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Affiliation(s)
- Athina-Marina Metaxa
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford OX2 6GG, UK
| | - Mike Clarke
- Northern Ireland Methodology Hub, Centre for Public Health, ICS-A Royal Hospitals, Belfast, Ireland, UK
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Murphy RJ, Muthukumaraswamy S, de Wit H. Microdosing Psychedelics: Current Evidence From Controlled Studies. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:500-511. [PMID: 38280630 DOI: 10.1016/j.bpsc.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/29/2024]
Abstract
Taking regular low doses of psychedelic drugs (microdosing) is a practice that has drawn recent scientific and media attention for its potential psychotherapeutic effects. Yet, controlled studies evaluating this practice have lagged. Here, we review recent evidence focusing on studies that were conducted with rigorous experimental control. Studies conducted under laboratory settings using double-blind placebo-controlled procedures and investigator-supplied drug were compiled. The review includes demographic characteristics of participants and dependent measures such as physiological, behavioral, and subjective effects of the drugs. Review criteria were met by 14 studies, all of which involved acute or repeated low (5-20 μg) doses of lysergic acid diethylamide (LSD). Acute microdoses of LSD dose-dependently altered blood pressure, sleep, neural connectivity, social cognition, mood, and perception of pain and time. Perceptible drug effects were reported at doses of 10 to 20 μg but not 5 μg. No serious adverse effects were reported. Repeated doses of LSD did not alter mood or cognition on any of the measures studied. The findings suggest that low doses of LSD are safe and produce acute behavioral and neural effects in healthy adults. Further studies are warranted to extend these findings to patient samples and to other psychedelic drugs and to investigate microdosing as a potential pharmacological treatment for psychiatric disorders.
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Affiliation(s)
- Robin J Murphy
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
| | - Suresh Muthukumaraswamy
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois
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Yao Y, Guo D, Lu TS, Liu FL, Huang SH, Diao MQ, Li SX, Zhang XJ, Kosten TR, Shi J, Bao YP, Lu L, Han Y. Efficacy and safety of psychedelics for the treatment of mental disorders: A systematic review and meta-analysis. Psychiatry Res 2024; 335:115886. [PMID: 38574699 DOI: 10.1016/j.psychres.2024.115886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/14/2024] [Accepted: 03/27/2024] [Indexed: 04/06/2024]
Abstract
We aim to systematically review and meta-analyze the effectiveness and safety of psychedelics [psilocybin, ayahuasca (active component DMT), LSD and MDMA] in treating symptoms of various mental disorders. Web of Science, Embase, EBSCO, and PubMed were searched up to February 2024 and 126 articles were finally included. Results showed that psilocybin has the largest number of articles on treating mood disorders (N = 28), followed by ayahuasca (N = 7) and LSD (N = 6). Overall, psychedelics have therapeutic effects on mental disorders such as depression and anxiety. Specifically, psilocybin (Hedges' g = -1.49, 95% CI [-1.67, -1.30]) showed the strongest therapeutic effect among four psychedelics, followed by ayahuasca (Hedges' g = -1.34, 95% CI [-1.86, -0.82]), MDMA (Hedges' g = -0.83, 95% CI [-1.33, -0.32]), and LSD (Hedges' g = -0.65, 95% CI [-1.03, -0.27]). A small amount of evidence also supports psychedelics improving tobacco addiction, eating disorders, sleep disorders, borderline personality disorder, obsessive-compulsive disorder, and body dysmorphic disorder. The most common adverse event with psychedelics was headache. Nearly a third of the articles reported that no participants reported lasting adverse effects. Our analyses suggest that psychedelics reduce negative mood, and have potential efficacy in other mental disorders, such as substance-use disorders and PTSD.
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Affiliation(s)
- Yuan Yao
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China; School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Dan Guo
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China; School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Tang-Sheng Lu
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China; School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Fang-Lin Liu
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China; School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Shi-Hao Huang
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China; School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Meng-Qi Diao
- School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Su-Xia Li
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Xiu-Jun Zhang
- School of Psychology, College of Public Health, North China University of Science and Technology, Tangshan 063210, Hebei Province, China
| | - Thomas R Kosten
- Department of Psychiatry, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jie Shi
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Yan-Ping Bao
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China.
| | - Lin Lu
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China; Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing 100191, China; Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China; Research Unit of Diagnosis and Treatment of Mood Cognitive Disorder, Chinese Academy of Medical Sciences (No.2018RU006).
| | - Ying Han
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China.
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Allen N, Jeremiah A, Murphy R, Sumner R, Forsyth A, Hoeh N, Menkes DB, Evans W, Muthukumaraswamy S, Sundram F, Roop P. LSD increases sleep duration the night after microdosing. Transl Psychiatry 2024; 14:191. [PMID: 38622150 PMCID: PMC11018829 DOI: 10.1038/s41398-024-02900-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 04/04/2024] [Accepted: 04/04/2024] [Indexed: 04/17/2024] Open
Abstract
Microdosing psychedelic drugs at a level below the threshold to induce hallucinations is an increasingly common lifestyle practice. However, the effects of microdosing on sleep have not been previously reported. Here, we report results from a Phase 1 randomized controlled trial in which 80 healthy adult male volunteers received a 6-week course of either LSD (10 µg) or placebo with doses self-administered every third day. Participants used a commercially available sleep/activity tracker for the duration of the trial. Data from 3231 nights of sleep showed that on the night after microdosing, participants in the LSD group slept an extra 24.3 min per night (95% Confidence Interval 10.3-38.3 min) compared to placebo-with no reductions of sleep observed on the dosing day itself. There were no changes in the proportion of time spent in various sleep stages or in participant physical activity. These results show a clear modification of the physiological sleep requirements in healthy male volunteers who microdose LSD. The clear, clinically significant changes in objective measurements of sleep observed are difficult to explain as a placebo effect. Trial registration: Australian New Zealand Clinical Trials Registry: A randomized, double-blind, placebo-controlled trial of repeated microdoses of lysergic acid diethylamide (LSD) in healthy volunteers; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381476 ; ACTRN12621000436875.
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Affiliation(s)
- Nathan Allen
- Faculty of Engineering, University of Auckland, Auckland, 1010, New Zealand.
| | - Aron Jeremiah
- Faculty of Engineering, University of Auckland, Auckland, 1010, New Zealand
| | - Robin Murphy
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Rachael Sumner
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Anna Forsyth
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Nicholas Hoeh
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland, 1023, New Zealand
| | - David B Menkes
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland, 1023, New Zealand
| | - William Evans
- Mana Health, 7 Ruskin St, Parnell, Auckland, 1052, New Zealand
| | - Suresh Muthukumaraswamy
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Frederick Sundram
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland, 1023, New Zealand
| | - Partha Roop
- Faculty of Engineering, University of Auckland, Auckland, 1010, New Zealand
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10
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Pop I, Dinkelacker J. Unlocking the self: Can microdosing psychedelics make one feel more authentic? NORDIC STUDIES ON ALCOHOL AND DRUGS 2024; 41:142-155. [PMID: 38645971 PMCID: PMC11027848 DOI: 10.1177/14550725231175353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/26/2023] [Indexed: 04/23/2024] Open
Abstract
Background and aim: In the present study, we focus on the relationship between state authenticity - the experience of being true to oneself in a particular moment - and microdosing - a practice that implies repeatedly ingesting very small doses of psychedelics that do not reach the threshold for perceptual alterations. We propose that microdosing could increase state authenticity through influencing people's mood and the number and satisfaction with daily activities. Methods: We used self-assessments of state authenticity collected from 18 microdosers in the Netherlands across the period of 1 month for a total of 192 observations. Results: We found that on the microdosing day and the day thereafter, state authenticity was significantly higher. Furthermore, the number of activities and the satisfaction with them were higher on the day when participants microdosed, while the following day only the number of activities was higher. Both the number or activities and the satisfaction with them were positively related to state authenticity. Conclusion: We propose that feeling and behaving authentically could have a central role in explaining the positive effects of microdosing on health and wellbeing that are reported by current research.
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Affiliation(s)
- Ioana Pop
- Tilburg University, Sociology Department, Tilburg, The Netherlands
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11
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Molla H, Lee R, Tare I, de Wit H. Greater subjective effects of a low dose of LSD in participants with depressed mood. Neuropsychopharmacology 2024; 49:774-781. [PMID: 38042914 PMCID: PMC10948752 DOI: 10.1038/s41386-023-01772-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 12/04/2023]
Abstract
Recent studies and anecdotal reports suggest that psychedelics can improve mood states, even at low doses. However, few placebo-controlled studies have examined the acute effects of low doses of LSD in individuals with psychiatric symptoms. In the current study, we examined the acute and sub-acute effect of a low dose of LSD (26 µg) on subjective effects and mood in volunteers with mild depressed mood. The study used a randomized, double-blind, crossover design to compare the effects of LSD in two groups of adults: participants who scored high (≥17; n = 20) or low (<17; n = 19) on the Beck Depression-II inventory (BDI) at screening. Participants received a single low dose of LSD (26 µg) and placebo during two 5-h laboratory sessions, separated by at least one week. Subjective, physiological, and mood measures were assessed at regular intervals throughout the sessions, and behavioral measures of creativity and emotion recognition were obtained at expected peak effect. BDI depression scores and mood ratings were assessed 48-h after each session. Relative to placebo, LSD (26 µg) produced expected, mild physiological and subjective effects on several measures in both groups. However, the high BDI group reported significantly greater drug effects on several indices of acute effects, including ratings of vigor, elation, and affectively positive scales of a measure of psychedelic effects (5D-ASC). The high BDI group also reported a greater decline in BDI depression scores 48-h after LSD, compared to placebo. These findings suggest that an acute low dose of LSD (26 µg) elicits more pronounced positive mood and stimulant-like effects, as well as stronger altered states of consciousness in individuals with depressive symptoms, compared to non-depressed individuals.
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Affiliation(s)
- Hanna Molla
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Ilaria Tare
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA.
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12
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Pop IA, Gielens E, Kottmann H, Achterberg P. Exploring the discourses around microdosing psychedelics within the r/microdosing online community. Soc Sci Med 2024; 347:116702. [PMID: 38520826 DOI: 10.1016/j.socscimed.2024.116702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 03/25/2024]
Abstract
In the present contribution, we examine the practice of microdosing psychedelics (microdosing) through textual analysis of the content produced by a dedicated online community, the r/microdosing subreddit. We collected a comprehensive dataset of publicly available submissions from this community and used structural topic modelling to identify and analyse the prevalent topics within the discussions. Through our analysis, we identified 16 distinct topics that mapped into clinical, human enhancement, as well as self-medication narratives. Notably, we found that the majority of discussions revolved around "how to" topics, supporting our argument that such online communities serve as essential information hubs, facilitating the dissemination of practical knowledge related to microdosing practices among the general population. The identified impact of the Covid-19 pandemic on the prevalence of discussion topics suggests that individuals within the online community may perceive microdosing primarily as a means of self-medication during times of heightened stress and uncertainty. Our findings contribute to the field of health sociology and psychedelic research by shedding light on the sociocultural factors influencing healthcare practices, including the role of online communities in facilitating processes of self-medicalization and self-medication.
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Affiliation(s)
- Ioana Andreea Pop
- Tilburg University, Sociology Department, PO BOX 90153, 5000 LE, Tilburg, the Netherlands.
| | - Erwin Gielens
- Tilburg University, Sociology Department, PO BOX 90153, 5000 LE, Tilburg, the Netherlands.
| | - Hannah Kottmann
- Tilburg University, Sociology Department, PO BOX 90153, 5000 LE, Tilburg, the Netherlands.
| | - Peter Achterberg
- Tilburg University, Sociology Department, PO BOX 90153, 5000 LE, Tilburg, the Netherlands.
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13
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Rouaud A, Calder AE, Hasler G. Microdosing psychedelics and the risk of cardiac fibrosis and valvulopathy: Comparison to known cardiotoxins. J Psychopharmacol 2024; 38:217-224. [PMID: 38214279 PMCID: PMC10944580 DOI: 10.1177/02698811231225609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Though microdosing psychedelics has become increasingly popular, its long-term effects on cardiac health remain unknown. Microdosing most commonly involves ingesting sub-threshold doses of lysergic acid diethylamide (LSD), psilocybin, or other psychedelic drugs 2-4 times a week for at least several weeks, but potentially months or years. Concerningly, both LSD and psilocybin share structural similarities with medications which raise the risk of cardiac fibrosis and valvulopathy when taken regularly, including methysergide, pergolide, and fenfluramine. 3,4-Methylenedioxymethamphetamine, which is also reportedly used for microdosing, is likewise associated with heart valve damage when taken chronically. In this review, we evaluate the evidence that microdosing LSD, psilocybin, and other psychedelics for several months or more could raise the risk of cardiac fibrosis. We discuss the relationship between drug-induced cardiac fibrosis and the 5-HT2B receptor, and we make recommendations for evaluating the safety of microdosing psychedelics in future studies.
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Affiliation(s)
- Antonin Rouaud
- University of Fribourg Center for Psychiatric Research, Fribourg, Switzerland
| | - Abigail E. Calder
- University of Fribourg Center for Psychiatric Research, Fribourg, Switzerland
| | - Gregor Hasler
- University of Fribourg Center for Psychiatric Research, Fribourg, Switzerland
- Lake Lucerne Institute, Vitznau, Switzerland
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14
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Yao H, Wang X, Chi J, Chen H, Liu Y, Yang J, Yu J, Ruan Y, Xiang X, Pi J, Xu JF. Exploring Novel Antidepressants Targeting G Protein-Coupled Receptors and Key Membrane Receptors Based on Molecular Structures. Molecules 2024; 29:964. [PMID: 38474476 DOI: 10.3390/molecules29050964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/29/2024] [Accepted: 02/09/2024] [Indexed: 03/14/2024] Open
Abstract
Major Depressive Disorder (MDD) is a complex mental disorder that involves alterations in signal transmission across multiple scales and structural abnormalities. The development of effective antidepressants (ADs) has been hindered by the dominance of monoamine hypothesis, resulting in slow progress. Traditional ADs have undesirable traits like delayed onset of action, limited efficacy, and severe side effects. Recently, two categories of fast-acting antidepressant compounds have surfaced, dissociative anesthetics S-ketamine and its metabolites, as well as psychedelics such as lysergic acid diethylamide (LSD). This has led to structural research and drug development of the receptors that they target. This review provides breakthroughs and achievements in the structure of depression-related receptors and novel ADs based on these. Cryo-electron microscopy (cryo-EM) has enabled researchers to identify the structures of membrane receptors, including the N-methyl-D-aspartate receptor (NMDAR) and the 5-hydroxytryptamine 2A (5-HT2A) receptor. These high-resolution structures can be used for the development of novel ADs using virtual drug screening (VDS). Moreover, the unique antidepressant effects of 5-HT1A receptors in various brain regions, and the pivotal roles of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and tyrosine kinase receptor 2 (TrkB) in regulating synaptic plasticity, emphasize their potential as therapeutic targets. Using structural information, a series of highly selective ADs were designed based on the different role of receptors in MDD. These molecules have the favorable characteristics of rapid onset and low adverse drug reactions. This review offers researchers guidance and a methodological framework for the structure-based design of ADs.
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Affiliation(s)
- Hanbo Yao
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Xiaodong Wang
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jiaxin Chi
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Haorong Chen
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Yilin Liu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jiayi Yang
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jiaqi Yu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Yongdui Ruan
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
| | - Xufu Xiang
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jiang Pi
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jun-Fa Xu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
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15
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Hagen EV, Schalomon M, Zhang Y, Hamilton TJ. Repeated microdoses of LSD do not alter anxiety or boldness in zebrafish. Sci Rep 2024; 14:4389. [PMID: 38388550 PMCID: PMC10883969 DOI: 10.1038/s41598-024-54676-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/15/2024] [Indexed: 02/24/2024] Open
Abstract
The therapeutic use of lysergic acid diethylamide (LSD) has resurfaced in the last decade, prompting further scientific investigation into its effectiveness in many animal models. Zebrafish (Danio rerio) are a popular model organism in medical sciences and are used to examine the repeated administration of pharmacological compounds. Previous zebrafish research found acute LSD altered behaviour and cortisol levels at high (250 µg/L) but not low (5-100 µg/L) levels. In this study, we used a motion tracking system to record and analyze the movement patterns of zebrafish after acute and repeated 10-day LSD exposure (1.5 µg/L, 15 µg/L, 150 µg/L) and after seven days of withdrawal. The open-field and novel object approach tests were used to examine anxiety-like behaviour, boldness, and locomotion. In the acute experiments we observed a significant decrease in high mobility with 1.5 µg/L, 15 µg/L, and 150 µg/L of LSD compared to the control and a decrease in velocity with 1.5 and 15 µg/L. In repeated experiments, there were no significant differences in the levels of anxiety, boldness, or locomotion between all LSD groups and controls immediately after 10-day treatment or after withdrawal.
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Affiliation(s)
- Ethan V Hagen
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Department of Psychology, MacEwan University, 10700 104 Ave NW, Edmonton, AB, T5J 4S2, Canada
| | - Melike Schalomon
- Department of Psychology, MacEwan University, 10700 104 Ave NW, Edmonton, AB, T5J 4S2, Canada
| | - Yanbo Zhang
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Trevor J Hamilton
- Department of Psychology, MacEwan University, 10700 104 Ave NW, Edmonton, AB, T5J 4S2, Canada.
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
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16
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Wells A, Muthukumaraswamy APS, Morunga E, Evans W, Cavadino A, Bansal M, Lawrence NJ, Ashley A, Hoeh NR, Sundram F, Applebaum AJ, Parkinson H, Reynolds L. PAM trial protocol: a randomised feasibility study of psychedelic microdosing-assisted meaning-centred psychotherapy in advanced stage cancer patients. Pilot Feasibility Stud 2024; 10:29. [PMID: 38347582 PMCID: PMC10860284 DOI: 10.1186/s40814-024-01449-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND An advanced cancer diagnosis can be associated with a significant profile of distress. Psychedelic compounds have shown clinically significant effects in the treatment of psychological distress in patients with advanced-stage cancer. Given the challenges of delivering timely and effective intervention in the advanced cancer context, it is possible that an alternative, more pragmatic, approach lies in psychedelic 'microdosing'. Microdosing refers to repeated administration of psychedelics in sub-hallucinogenic doses. The purpose of this study is to evaluate the feasibility of conducting a full-scale randomised controlled trial comparing psychedelic microdose-assisted-meaning-centred psychotherapy (PA-MCP) to standard meaning-centred psychotherapy (MCP) in New Zealand indigenous (Māori) and non-indigenous people with advanced cancer and symptoms of anxiety and/or depression. Although MCP is a well-established psychotherapeutic treatment in advanced cancer populations, the potential efficacy and effectiveness of this therapy when delivered alongside a standardised microdose regimen of a psychedelic compound have not been investigated. METHODS Participants with advanced-stage cancer and symptoms of anxiety and/or depression (N = 40; 20 Māori, 20 non-Māori) will be randomised under double-blind conditions to receive 7 sessions of MCP alongside 13 doses of either an LSD microdose (4-20 µg) (PA-MCP) or inactive placebo (placebo-MCP). The feasibility, acceptability, and safety of this intervention and physiological and psychological measures will be recorded at baseline, at each session of MCP, and at a 1-month and 6-month follow-up. DISCUSSION Our findings will evaluate the feasibility, acceptability, and safety of a larger randomised controlled trial and provide an initial indication of the potential benefits of psychedelic microdosing for psychological distress in advanced-stage indigenous and non-indigenous cancer patients. TRIAL REGISTRATION NZCTR, ACTRN12623000478617. Registered 11 May 2023. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385810&isReview=true .
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Affiliation(s)
- Alesha Wells
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 22-30 Park Avenue, Grafton, Auckland, 1023, New Zealand.
| | - A P Suresh Muthukumaraswamy
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Eva Morunga
- Cancer Support Service, Te Toka Tumai Auckland, Auckland City Hospital, Te Whatu Ora2 Park Road, Grafton, Auckland, 1023, New Zealand
- The University of Auckland, 22-30 Park Avenue, Grafton, Auckland, 1023, New Zealand
| | - Will Evans
- Mana Health, 7 Ruskin Street, Parnell, Auckland, 1052, New Zealand
| | - Alana Cavadino
- School of Population Health, The University of Auckland, 22-30 Park Avenue, Grafton, Auckland, 1023, New Zealand
| | - Mahima Bansal
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Nicola J Lawrence
- Department of Oncology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, New Zealand
- Te Pūriri o Te Ora - Regional Cancer and Blood, Te Whatu Ora Te Toka Tumai, 2 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Amanda Ashley
- Te Pūriri o Te Ora - Regional Cancer and Blood, Te Whatu Ora Te Toka Tumai, 2 Park Road, Grafton, Auckland, 1023, New Zealand
- Harbour Cancer and Wellness, 212 Wairau Road, Wairau Valley, Auckland, 0627, New Zealand
| | - Nicholas R Hoeh
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 22-30 Park Avenue, Grafton, Auckland, 1023, New Zealand
| | - Frederick Sundram
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 22-30 Park Avenue, Grafton, Auckland, 1023, New Zealand
| | - Allison J Applebaum
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan Kettering Cancer Center, 641 Lexington Avenue, 7th Floor, New York, NY, 10022, USA
| | - Hineatua Parkinson
- School of Psychology, University of Auckland, 23 Symonds Street, Auckland Central, 1010, New Zealand
| | - Lisa Reynolds
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 22-30 Park Avenue, Grafton, Auckland, 1023, New Zealand
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17
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Harlow AF, Hendricks PS, Leventhal AM, Barrington-Trimis JL. Psychedelic Microdosing among Young Adults from Southern California. J Psychoactive Drugs 2024:1-12. [PMID: 38341607 PMCID: PMC11315810 DOI: 10.1080/02791072.2024.2313684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024]
Abstract
Despite common depictions in the media, there is little scientific evidence on microdosing psychedelic drugs. We assessed awareness, prevalence, and dosing practices of microdosing psychedelic drugs among young adults 18-22 years old from Southern California (2018-2019). We examined whether sociodemographic factors, personality traits, mental health, or other substance use behaviors were correlated with having ever microdosed. Among 2,396 participants, 293 (12%) had heard of microdosing and 74 (3%) ever microdosed. Among those who had heard of microdosing, 79% correctly defined microdosing as taking an amount of a psychedelic much lower than a standard dose, whereas 15% misperceived microdosing as a standard psychedelic dose. Psilocybin was the most common drug ever microdosed (70%), followed by lysergic acid diethylamide (LSD, 57%). Among those who ever microdosed, ~18% reported using psychoactive doses far higher than would be generally considered a microdose. White race, male/masculine gender identity, bisexual identity, past 6-month other drug use, greater attention deficit/hyperactivity disorder symptoms, mindfulness, and sensation-seeking were positively associated with having ever microdosed in multivariable models. Young adult microdosing merits further attention from scientific and public health professionals to help prevent misperceptions and potential adverse consequences as well as explore its potential therapeutic applications.
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Affiliation(s)
- Alyssa F. Harlow
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
- Institute for Addiction Science, University of Southern California, Los Angeles, CA, USA
| | - Peter S. Hendricks
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Adam M. Leventhal
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
- Institute for Addiction Science, University of Southern California, Los Angeles, CA, USA
| | - Jessica L. Barrington-Trimis
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
- Institute for Addiction Science, University of Southern California, Los Angeles, CA, USA
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18
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Petranker R, Anderson T, Fewster EC, Aberman Y, Hazan M, Gaffrey M, Seli P. Keeping the promise: a critique of the current state of microdosing research. Front Psychiatry 2024; 15:1217102. [PMID: 38374976 PMCID: PMC10875010 DOI: 10.3389/fpsyt.2024.1217102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 01/05/2024] [Indexed: 02/21/2024] Open
Abstract
Introduction The practice of taking small, sub-hallucinogenic doses of psychedelics, known as microdosing, has exploded in popularity over the last decade. Users claim benefits ranging from improved mood and enhanced creativity to an increased sense of meaning and connectedness in life. While research on microdosing is still lagging behind the shift in public opinion, several papers have been published in the last five years which attempted to assess the effects of microdosing. Methods This review paper aimed to critically analyze the research practices used in the recent wave of microdosing research: We reviewed 15 papers published before the closing date of this review in March 2022. Results Our review concludes that it is premature to draw any conclusions about the efficacy or safety of microdosing since the research quality cannot be considered confirmatory. Discussion We propose some potential causes for the current state of the literature and some suggestions for how these causes may be ameliorated.
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Affiliation(s)
- Rotem Petranker
- Department of Psychology, Neuroscience and Behaviour, Hamilton, ON, Canada
| | - Thomas Anderson
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | | | | | - Marik Hazan
- Independent Researcher, New York, NY, United States
| | - Michael Gaffrey
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States
| | - Paul Seli
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States
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19
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Duan W, Cao D, Wang S, Cheng J. Serotonin 2A Receptor (5-HT 2AR) Agonists: Psychedelics and Non-Hallucinogenic Analogues as Emerging Antidepressants. Chem Rev 2024; 124:124-163. [PMID: 38033123 DOI: 10.1021/acs.chemrev.3c00375] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Psychedelics make up a group of psychoactive compounds that induce hallucinogenic effects by activating the serotonin 2A receptor (5-HT2AR). Clinical trials have demonstrated the traditional psychedelic substances like psilocybin as a class of rapid-acting and long-lasting antidepressants. However, there is a pressing need for rationally designed 5-HT2AR agonists that possess optimal pharmacological profiles in order to fully reveal the therapeutic potential of these agonists and identify safer drug candidates devoid of hallucinogenic effects. This Perspective provides an overview of the structure-activity relationships of existing 5-HT2AR agonists based on their chemical classifications and discusses recent advancements in understanding their molecular pharmacology at a structural level. The encouraging clinical outcomes of psychedelics in depression treatment have sparked drug discovery endeavors aimed at developing novel 5-HT2AR agonists with improved subtype selectivity and signaling bias properties, which could serve as safer and potentially nonhallucinogenic antidepressants. These efforts can be significantly expedited through the utilization of structure-based methods and functional selectivity-directed screening.
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Affiliation(s)
- Wenwen Duan
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Dongmei Cao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Sheng Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Jianjun Cheng
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
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20
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Zaretsky TG, Jagodnik KM, Barsic R, Antonio JH, Bonanno PA, MacLeod C, Pierce C, Carney H, Morrison MT, Saylor C, Danias G, Lepow L, Yehuda R. The Psychedelic Future of Post-Traumatic Stress Disorder Treatment. Curr Neuropharmacol 2024; 22:636-735. [PMID: 38284341 PMCID: PMC10845102 DOI: 10.2174/1570159x22666231027111147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 01/30/2024] Open
Abstract
Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.
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Affiliation(s)
- Tamar Glatman Zaretsky
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kathleen M. Jagodnik
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Robert Barsic
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Josimar Hernandez Antonio
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Philip A. Bonanno
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Carolyn MacLeod
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Charlotte Pierce
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hunter Carney
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Morgan T. Morrison
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Charles Saylor
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George Danias
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lauren Lepow
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rachel Yehuda
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
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21
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Tsugiyama LE, Moraes RCM, Moraes YAC, Francis-Oliveira J. Promising new pharmacological targets for depression: The search for efficacy. Drug Discov Today 2023; 28:103804. [PMID: 37865307 DOI: 10.1016/j.drudis.2023.103804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/31/2023] [Accepted: 10/16/2023] [Indexed: 10/23/2023]
Abstract
Pharmacological treatment of major depressive disorder (MDD) still relies on the use of serotonergic drugs, despite their limited efficacy. A few mechanistically new drugs have been developed in recent years, but many fail in clinical trials. Several hypotheses have been proposed to explain MDD pathophysiology, indicating that physiological processes such as neuroplasticity, circadian rhythms, and metabolism are potential targets. Here, we review the current state of pharmacological treatments for MDD, as well as the preclinical and clinical evidence for an antidepressant effect of molecules that target non-serotonergic systems. We offer some insights into the challenges facing the development of new antidepressant drugs, and the prospect of finding more effectiveness for each target discussed.
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Affiliation(s)
- Lucila Emiko Tsugiyama
- Kansai Medical University, Graduate School of Medicine, iPS Cell Applied Medicine, Hirakata, Osaka, Japan
| | - Ruan Carlos Macedo Moraes
- University of Alabama at Birmingham, Department of Psychiatry and Behavioral Neurobiology, Birmingham, AL, USA; Biomedical Sciences Institute, Department of Human Physiology, Sao Paulo University, Sao Paulo, Brazil
| | | | - Jose Francis-Oliveira
- University of Alabama at Birmingham, Department of Psychiatry and Behavioral Neurobiology, Birmingham, AL, USA; Biomedical Sciences Institute, Department of Human Physiology, Sao Paulo University, Sao Paulo, Brazil.
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22
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Wsół A. Cardiovascular safety of psychedelic medicine: current status and future directions. Pharmacol Rep 2023; 75:1362-1380. [PMID: 37874530 PMCID: PMC10661823 DOI: 10.1007/s43440-023-00539-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/02/2023] [Accepted: 10/02/2023] [Indexed: 10/25/2023]
Abstract
Psychedelics are powerful psychoactive substances that alter perception and mood processes. Their effectiveness in the treatment of psychiatric diseases was known before their prohibition. An increasing number of recent studies, due to the indisputable resurgence of serotonergic hallucinogens, have shown their efficacy in alleviating depression, anxiety, substance abuse therapies, and existential distress treatment in patients facing life-threatening illness. Psychedelics are generally considered to be physiologically safe with low toxicity and low addictive potential. However, their agonism at serotonergic receptors should be considered in the context of possible serotonin-related cardiotoxicity (5-HT2A/2B and 5-HT4 receptors), influence on platelet aggregation (5-HT2A receptor), and their proarrhythmic potential. The use of psychedelics has also been associated with significant sympathomimetic effects in both experimental and clinical studies. Therefore, the present review aims to provide a critical discussion of the cardiovascular safety of psilocybin, d-lysergic acid diethylamide (LSD), N,N-dimethyltryptamine, ayahuasca, and mescaline, based on the results of experimental research and clinical trials in humans. Experimental studies provide inconsistent information on the potential cardiovascular effects and toxicity of psychedelics. Data from clinical trials point to the relative cardiovascular safety of psychedelic-assisted therapies in the population of "healthy" volunteers. However, there is insufficient evidence from therapies carried out with microdoses of psychedelics, and there is still a lack of data on the safety of psychedelics in the population of patients with cardiovascular disease. Therefore, the exact determination of the cardiovascular safety of psychedelic therapies (especially long-term therapies) requires further research.
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Affiliation(s)
- Agnieszka Wsół
- Chair and Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Banacha 1B, 02-097, Warsaw, Poland.
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23
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Pouyan N, Younesi Sisi F, Kargar A, Scheidegger M, McIntyre RS, Morrow JD. The effects of Lysergic Acid Diethylamide (LSD) on the Positive Valence Systems: A Research Domain Criteria (RDoC)-Informed Systematic Review. CNS Drugs 2023; 37:1027-1063. [PMID: 37999867 PMCID: PMC10703966 DOI: 10.1007/s40263-023-01044-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/16/2023] [Indexed: 11/25/2023]
Abstract
BACKGROUND AND OBJECTIVES The renewed interest in psychedelic research provides growing evidence of potentially unique effects on various aspects of reward processing systems. Using the Research Domain Criteria (RDoC) framework, as proposed by the National Institute of Mental Health, we aim to synthesize the existing literature concerning the impact of lysergic acid diethylamide (LSD) on the RDoC's Positive Valence Systems (PVS) domain, and to identify potential avenues for further research. METHODS Two LSD-related terms (lysergic acid diethylamide and LSD) and 13 PVS-related terms (reward, happiness, bliss, motivation, reinforcement learning, operant, conditioning, satisfaction, decision making, habit, valence, affect, mood) were used to search electronic databases such as PubMed, Scopus, PsychINFO, and Web of Science for relevant articles. A manual search of the reference list resulted in nine additional articles. After screening, articles and data were evaluated and included based on their relevance to the objective of investigating the effects of LSD on the PVS. Articles and data were excluded if they did not provide information about the PVS, were observational in nature, lacked comparators or reference groups, or were duplicates. A risk of bias assessment was performed using the National Toxicology Program's Office of Health Assessment and Translation (NTP OHAT) risk of bias (RoB) tool. Data from the included articles were collected and structured based on the RDoC bio-behavioral matrix, specifically focusing on the PVS domain and its three constituent constructs: reward responsiveness, reward learning, and reward valuation. RESULTS We reviewed 28 clinical studies with 477 participants. Lysergic acid diethylamide, assessed at self-report (23 studies), molecular (5 studies), circuit (4 studies), and paradigm (3 studies) levels, exhibited dose-dependent mood improvement (20 short-term and 3 long-term studies). The subjective and neural effects of LSD were linked to the 5-HT2A receptor (molecular). Animal studies (14 studies) suggested LSD could mildly reinforce conditioned place preference without aversion and reduce responsiveness to other rewards. Findings on reward learning were inconsistent but hinted at potential associative learning enhancements. Reward valuation measures indicated potential reductions in effort expenditure for other reinforcers. CONCLUSION Our findings are consistent with our previous work, which indicated classical psychedelics, primarily serotonin 2A receptor agonists, enhanced reward responsiveness in healthy individuals and patient populations. Lysergic acid diethylamide exhibits a unique profile in the reward learning and valuation constructs. Using the RDoC-based framework, we identified areas for future research, enhancing our understanding of the impact of LSD on reward processing. However, applying RDoC to psychedelic research faces limitations due to diverse study designs that were not initially RDoC-oriented. Limitations include subjective outcome measure selection aligned with RDoC constructs and potential bias in synthesizing varied studies. Additionally, some human studies were open-label, introducing potential bias compared to randomized, blinded studies.
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Affiliation(s)
- Niloufar Pouyan
- Michigan Psychedelic Center (M-PsyC), and Chronic Pain and Fatigue Research Center (CPFRC), University of Michigan Medical School, Ann Arbor, MI, USA.
- Neuroscience Graduate Program, and Program in Biomedical Sciences (PIBS), University of Michigan Medical School, 1135 Catherine Street, Box 5619, 2960 Taubman Health Science Library, Ann Arbor, MI, USA.
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland.
- Aracell Zist Darou pharmaceutical, Tehran, Iran.
| | - Farnaz Younesi Sisi
- Yaadmaan Institute for Brain, Cognition and Memory Studies, Tehran, Iran
- Cognitive Neurology and Neuropsychiatry Research Center, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Alireza Kargar
- Cognitive Neurology and Neuropsychiatry Research Center, Tehran University of Medical Sciences (TUMS), Tehran, Iran
- Department of Clinical Pharmacy, School of pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Milan Scheidegger
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit (MDPU), University Health Network, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Jonathan D Morrow
- Neuroscience Graduate Program, and Program in Biomedical Sciences (PIBS), University of Michigan Medical School, 1135 Catherine Street, Box 5619, 2960 Taubman Health Science Library, Ann Arbor, MI, USA
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
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24
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Donegan CJ, Daldegan-Bueno D, Sumner R, Menkes D, Evans W, Hoeh N, Sundram F, Reynolds L, Ponton R, Cavadino A, Smith T, Roop P, Allen N, Abeysinghe B, Svirskis D, Forsyth A, Bansal M, Muthukumaraswamy S. An open-label pilot trial assessing tolerability and feasibility of LSD microdosing in patients with major depressive disorder (LSDDEP1). Pilot Feasibility Stud 2023; 9:169. [PMID: 37798662 PMCID: PMC10552250 DOI: 10.1186/s40814-023-01399-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/13/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Globally, an estimated 260 million people suffer from depression [1], and there is a clear need for the development of new, alternative antidepressant therapies. In light of problems with the tolerability and efficacy of available treatments [2], a global trend is emerging for patients to self-treat depression with microdoses of psychedelic drugs such as lysergic acid diethylamide (LSD) and psilocybin [3]. Beyond anecdotal reports from those who self-medicate in this way, few clinical trials have evaluated this practice. In our recently published phase 1 study in healthy volunteers [4], we determined that LSD microdosing was relatively safe and well tolerated in that cohort. Furthermore, the data demonstrated that conducting such microdosing trials is broadly feasible, with excellent adherence and compliance to the regimen observed. In this open-label pilot trial of patients with major depressive disorder (LSDDEP1), we will test the tolerability and feasibility of an 8-week regimen of LSD microdosing in this patient group prior to a larger subsequent randomised controlled trial (LSDDEP2). METHODS Twenty patients meeting the DSM-5 criteria for major depressive disorder will receive an 8-week LSD microdosing treatment regimen. The treatment protocol will use a sublingual formulation of LSD (MB-22001) delivered twice per week under a titration schedule using a dose of 5-15 µg. Tolerability will be assessed by quantifying the percentage of participants who withdraw from the trial due to adverse events attributable to the treatment regimen, while feasibility will be assessed by quantifying the percentage of attended clinic visits once enrolled. To determine whether there is any antidepressant response to the LSD microdosing regimen, MADRS scores will be assessed at baseline and 2, 4, 6, and 8 weeks after the commencement of the regimen. DISCUSSION The results of LSDDEP1 will provide valuable information regarding the tolerability and feasibility of a proposed LSD microdosing regimen in patients with MDD. Such information is critically important to optimise trial design prior to commencing a subsequent and more resource-intensive randomised controlled trial. TRIAL REGISTRATION ANZCTR, ACTRN12623000486628. Registered on 12 May 2023.
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Affiliation(s)
- Carina Joy Donegan
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 2 Park Road, Grafton, Auckland, 1023, New Zealand.
| | - Dimitri Daldegan-Bueno
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Rachael Sumner
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - David Menkes
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, Waikato, Clinical Campus, University of Auckland, Pembroke Street, Hamilton, 3240, New Zealand
| | - William Evans
- Mana Health, 7 Ruskin St, Parnell, Auckland, 1052, New Zealand
| | - Nicholas Hoeh
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 2 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Frederick Sundram
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 2 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Lisa Reynolds
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, 2 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Rhys Ponton
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Alana Cavadino
- School of Population Health, Faculty of Medical and Health Sciences, University of Auckland, 2 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Todd Smith
- Te Whatu Ora, Auckland, 1023, New Zealand
| | - Partha Roop
- Faculty of Engineering, University of Auckland, Auckland, 1023, New Zealand
| | - Nathan Allen
- Faculty of Engineering, University of Auckland, Auckland, 1023, New Zealand
| | - Binu Abeysinghe
- Faculty of Engineering, University of Auckland, Auckland, 1023, New Zealand
| | - Darren Svirskis
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Anna Forsyth
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Mahima Bansal
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand
| | - Suresh Muthukumaraswamy
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, 1023, New Zealand.
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25
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Hirschfeld T, Prugger J, Majić T, Schmidt TT. Dose-response relationships of LSD-induced subjective experiences in humans. Neuropsychopharmacology 2023; 48:1602-1611. [PMID: 37161078 PMCID: PMC10516880 DOI: 10.1038/s41386-023-01588-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 03/19/2023] [Accepted: 04/12/2023] [Indexed: 05/11/2023]
Abstract
Lysergic acid diethylamide (LSD) is a potent classic serotonergic psychedelic, which facilitates a variety of altered states of consciousness. Here we present the first meta-analysis establishing dose-response relationship estimates of the altered states of consciousness induced by LSD. Data extracted from articles identified by a systematic literature review following PRISMA guidelines were obtained from the Altered States Database. The psychometric data comprised ratings of subjective effects from standardized and validated questionnaires: the Altered States of Consciousness Rating Scale (5D-ASC, 11-ASC) and the Mystical Experience Questionnaire (MEQ30). We performed meta-regression analyses using restricted cubic splines for data from studies with LSD doses of up to 200 μg base. Most scales revealed a sigmoid-like increase of effects, with a plateauing at around 100 μg. The most strongly modulated factors referred to changes in perception and illusory imagination, followed by positively experienced ego-dissolution, while only small effects were found for Anxiety and Dread of Ego Dissolution. The considerable variability observed in most factors and scales points to the role of non-pharmacological factors in shaping subjective experiences. The established dose-response relationships may be used as general references for future experimental and clinical research on LSD to compare observed with expected subjective effects and to elucidate phenomenological differences between psychedelics.
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Affiliation(s)
- Tim Hirschfeld
- Psychedelic Substances Research Group, Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Johanna Prugger
- Psychedelic Substances Research Group, Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Berlin, Germany
- International Graduate Program Medical Neurosciences, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Tomislav Majić
- Psychedelic Substances Research Group, Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Department of Psychiatry und Neurosciences, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Timo T Schmidt
- Psychedelic Substances Research Group, Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Berlin, Germany.
- Department of Education and Psychology, Freie Universität Berlin, 14195, Berlin, Germany.
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26
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Murphy RJ, Sumner R, Evans W, Ponton R, Ram S, Godfrey K, Forsyth A, Cavadino A, Krishnamurthy Naga V, Smith T, Hoeh NR, Menkes DB, Muthukumaraswamy S. Acute Mood-Elevating Properties of Microdosed Lysergic Acid Diethylamide in Healthy Volunteers: A Home-Administered Randomized Controlled Trial. Biol Psychiatry 2023; 94:511-521. [PMID: 36997080 DOI: 10.1016/j.biopsych.2023.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 04/01/2023]
Abstract
BACKGROUND Microdosing psychedelic drugs is a widespread social phenomenon with diverse benefits claimed for mood and cognition. Randomized controlled trials have failed to support these claims, but the laboratory-based dosing in trials conducted to date may have limited ecological validity. METHODS Healthy male volunteers were randomized into lysergic acid diethylamide (LSD) (n = 40) and placebo (n = 40) groups and received 14 doses of either 10 μg LSD or an inactive placebo every 3 days for 6 weeks. First doses were given in a supervised laboratory setting, with other doses self-administered in a naturalistic setting. Results of safety data, blinding, daily questionnaires, expectancy, and pre-/postintervention psychometrics and cognitive tasks are presented here. RESULTS The most notable reported adverse event was treatment-related anxiety, which prompted the withdrawal of 4 participants from the LSD group. Daily questionnaires showed credible evidence (>99% posterior probability) of improved ratings of creativity, connectedness, energy, happiness, irritability, and wellness on dose days compared with nondose days, and these effects remained when controlling for preintervention expectancy. No questionnaire or cognitive task showed a credible change between baseline and 6-week assessment time points. CONCLUSIONS Microdosing LSD appears to be relatively safe in healthy adult men, notwithstanding a risk of anxiety. While microdosing elicited transient increases in scales associated with mood-elevating effects, it was not sufficient to promote enduring changes to overall mood or cognition in healthy adults. Future microdosing trials in clinical populations will require the use of active placebos to control for placebo effects and dose titration to adjust for interindividual variability in drug response.
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Affiliation(s)
- Robin J Murphy
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
| | - Rachael Sumner
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | | | - Rhys Ponton
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Sanya Ram
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Kate Godfrey
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand; Centre for Psychedelic Research, Department of Psychiatry, Imperial College London, London, England, UK
| | - Anna Forsyth
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Alana Cavadino
- Epidemiology and Biostatistics, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Venkat Krishnamurthy Naga
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | | | - Nicholas R Hoeh
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - David B Menkes
- Department of Psychological Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Suresh Muthukumaraswamy
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
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27
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Bershad AK, de Wit H. Social Psychopharmacology: Novel Approaches to Treat Deficits in Social Motivation in Schizophrenia. Schizophr Bull 2023; 49:1161-1173. [PMID: 37358825 PMCID: PMC10483474 DOI: 10.1093/schbul/sbad094] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
BACKGROUND AND HYPOTHESIS Diminished social motivation is a negative symptom of schizophrenia and leads to severe functional consequences for many patients suffering from the illness. However, there are no effective medications available to treat this symptom. Despite the lack of approved treatments for patients, there is a growing body of literature on the effects of several classes of drugs on social motivation in healthy volunteers that may be relevant to patients. The aim of this review is to synthesize these results in an effort to identify novel directions for the development of medications to treat reduced social motivation in schizophrenia. STUDY DESIGN In this article, we review pharmacologic challenge studies addressing the acute effects of psychoactive drugs on social motivation in healthy volunteers and consider how these findings may be applied to deficits in social motivation in schizophrenia. We include studies testing amphetamines and 3,4-methylenedioxymethamphetamine (MDMA), opioids, cannabis, serotonergic psychedelics, antidepressants, benzodiazepines, and neuropeptides. STUDY RESULTS We report that amphetamines, MDMA, and some opioid medications enhance social motivation in healthy adults and may represent promising avenues of investigation in schizophrenia. CONCLUSIONS Given the acute effects of these drugs on behavioral and performance-based measures of social motivation in healthy volunteers, they may be particularly beneficial as an adjunct to psychosocial training programs in patient populations. It remains to be determined how these medications affect patients with deficits in social motivation, and in which contexts they may be most effectively administered.
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Affiliation(s)
- Anya K Bershad
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles Semel Institute for Neuroscience and Human Behavior, Los Angeles, CAUSA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, ILUSA
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28
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Tagen M, Mantuani D, van Heerden L, Holstein A, Klumpers LE, Knowles R. The risk of chronic psychedelic and MDMA microdosing for valvular heart disease. J Psychopharmacol 2023; 37:876-890. [PMID: 37572027 DOI: 10.1177/02698811231190865] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/14/2023]
Abstract
Psychedelic microdosing is the practice of taking very low doses of psychedelic substances, typically over a longer period of time. The long-term safety of chronic microdosing is relatively uncharacterized, but valvular heart disease (VHD) has been proposed as a potential risk due to activation of the serotonin 5-HT2B receptor. However, this risk has not yet been comprehensively assessed. This analysis searched for all relevant in vitro, animal, and clinical studies related to the VHD risk of lysergic acid diethylamide (LSD), psilocybin, mescaline, N,N-dimethyltryptamine (DMT), and the non-psychedelic 3,4-methylenedioxymethamphetamine (MDMA). All five compounds and some metabolites could bind to the 5-HT2B receptor with potency equal to or greater than that of the 5-HT2A receptor, the primary target of psychedelics. All compounds were partial agonists at the 5-HT2B receptor with the exception of mescaline, which could not be adequately assessed due to low potency. Safety margins relative to the maximum plasma concentrations from typical microdoses were greater than known valvulopathogens, but not without potential risk. No animal or clinical studies appropriately designed to evaluate VHD risk were found for the four psychedelics. However, there is some clinical evidence that chronic ingestion of full doses of MDMA is associated with VHD. We conclude that VHD is a potential risk with chronic psychedelic microdosing, but further studies are necessary to better define this risk.
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Affiliation(s)
| | - Daniel Mantuani
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
| | - Liron van Heerden
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
| | - Alex Holstein
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
| | - Linda E Klumpers
- Verdient Science LLC, Englewood, CO, USA
- Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Richard Knowles
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
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Inserra A, Piot A, De Gregorio D, Gobbi G. Lysergic Acid Diethylamide (LSD) for the Treatment of Anxiety Disorders: Preclinical and Clinical Evidence. CNS Drugs 2023; 37:733-754. [PMID: 37603260 DOI: 10.1007/s40263-023-01008-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2023] [Indexed: 08/22/2023]
Abstract
Anxiety disorders (ADs) represent the sixth leading cause of disability worldwide, resulting in a significant global economic burden. Over 50% of individuals with ADs do not respond to standard therapies, making the identification of more effective anxiolytic drugs an ongoing research priority. In this work, we review the preclinical literature concerning the effects of lysergic acid diethylamide (LSD) on anxiety-like behaviors in preclinical models, and the clinical literature on anxiolytic effects of LSD in healthy volunteers and patients with ADs. Preclinical and clinical findings show that even if LSD may exacerbate anxiety acutely (both in "microdoses" and "full doses"), it induces long-lasting anxiolytic effects. Only two randomized controlled trials combining LSD and psychotherapy have been performed in patients with ADs with and without life-threatening conditions, showing a good safety profile and persisting decreases in anxiety outcomes. The effect of LSD on anxiety may be mediated by serotonin receptors (5-HT1A/1B, 5-HT2A/2C, and 5-HT7) and/or transporter in brain networks and circuits (default mode network, cortico-striato-thalamo-cortical circuit, and prefrontal cortex-amygdala circuit), involved in the modulation of anxiety. It remains unclear whether LSD can be an efficacious treatment alone or only when combined with psychotherapy, and if "microdosing" may elicit the same sustained anxiolytic effects as the "full doses". Further randomized controlled trials with larger sample size cohorts of patients with ADs are required to clearly define the effective regimens, safety profile, efficacy, and feasibility of LSD for the treatment of ADs.
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Affiliation(s)
- Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Avenue des Pins Ouest, Montreal, QC, H3A 1A1, Canada
| | - Alexandre Piot
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Danilo De Gregorio
- Division of Neuroscience, Vita-Salute San Raffaele University, Milan, Italy
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Avenue des Pins Ouest, Montreal, QC, H3A 1A1, Canada.
- McGill University Health Center, Montreal, QC, Canada.
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Pilozzi A, Foster S, Mischoulon D, Fava M, Huang X. A Brief Review on the Potential of Psychedelics for Treating Alzheimer's Disease and Related Depression. Int J Mol Sci 2023; 24:12513. [PMID: 37569888 PMCID: PMC10419627 DOI: 10.3390/ijms241512513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 08/03/2023] [Accepted: 08/05/2023] [Indexed: 08/13/2023] Open
Abstract
Alzheimer's disease (AD), the most common form of senile dementia, is poised to place an even greater societal and healthcare burden as the population ages. With few treatment options for the symptomatic relief of the disease and its unknown etiopathology, more research into AD is urgently needed. Psychedelic drugs target AD-related psychological pathology and symptoms such as depression. Using microdosing, psychedelic drugs may prove to help combat this devastating disease by eliciting psychiatric benefits via acting through various mechanisms of action such as serotonin and dopamine pathways. Herein, we review the studied benefits of a few psychedelic compounds that may show promise in treating AD and attenuating its related depressive symptoms. We used the listed keywords to search through PubMed for relevant preclinical, clinical research, and review articles. The putative mechanism of action (MOA) for psychedelics is that they act mainly as serotonin receptor agonists and induce potential beneficial effects for treating AD and related depression.
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Affiliation(s)
- Alexander Pilozzi
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Simmie Foster
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
- Depression Clinical & Research Program, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - David Mischoulon
- Depression Clinical & Research Program, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Maurizio Fava
- Depression Clinical & Research Program, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Xudong Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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Hossain M, Sulochana SP, Heath KE, Bari SMI, Brewster P, Barnes J, Munivar A, Walker GM, Puleo DA, Werfel TA. Interval delivery of 5HT 2A agonists using multilayered polymer films. J Biomed Mater Res A 2023; 111:790-800. [PMID: 36606344 PMCID: PMC10101876 DOI: 10.1002/jbm.a.37497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/07/2022] [Accepted: 12/29/2022] [Indexed: 01/07/2023]
Abstract
There is an urgent unmet medical need to develop therapeutic options for the ~50% of depression patients suffering from treatment-resistant depression, which is difficult to treat with existing psycho- and pharmaco-therapeutic options. Classical psychedelics, such as the 5HT2A agonists, have re-emerged as a treatment paradigm for depression. Recent clinical trials highlight the potential effectiveness of 5HT2A agonists to improve mood and psychotherapeutic growth in treatment-resistant depression patients, even in those who have failed a median of four previous medications in their lifetime. Moreover, microdosing could be a promising way to achieve long-term alleviation of depression symptoms without a hallucinogenic experience. However, there are a gamut of practical barriers that stymie further investigation of microdosing 5HT2A agonists, including: low compliance with the complicated dosing regimen, high risk of diversion of controlled substances, and difficulty and cost administering the long-term treatment regimens in controlled settings. Here, we developed a drug delivery system composed of multilayered cellulose acetate phthalate (CAP)/Pluronic F-127 (P) films for the encapsulation and interval delivery of 5HT2A agonists from a fully biodegradable and biocompatible implant. CAPP film composition, thickness, and layering strategies were optimized, and we demonstrated three distinct pulses from the multilayered CAPP films in vitro. Additionally, the pharmacokinetics and biodistribution of the 5HT2A agonist 2,5-Dimethoxy-4-iodoamphetamine (DOI) were quantified following the subcutaneous implantation of DOI-loaded single and multilayered CAPP films. Our results demonstrate, for the first time, the interval delivery of psychedelics from an implantable drug delivery system and open the door to future studies into the therapeutic potential of psychedelic delivery.
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Affiliation(s)
- Mehjabeen Hossain
- Department of BioMolecular Sciences, University of Mississippi, University, Mississippi, USA
| | - Suresh P Sulochana
- Center of Biomedical Research Excellence in Natural Products Neuroscience, University of Mississippi, University, Mississippi, USA
| | - Katie E Heath
- Center of Biomedical Research Excellence in Natural Products Neuroscience, University of Mississippi, University, Mississippi, USA
| | | | - Parker Brewster
- Department of Biomedical Engineering, University of Mississippi, University, Mississippi, USA
| | - Jared Barnes
- Department of Biomedical Engineering, University of Mississippi, University, Mississippi, USA
| | - Azim Munivar
- Research and Development, BioHaven Pharmaceuticals, Inc, New Haven, Connecticut, USA
| | - Glenn M Walker
- Department of Biomedical Engineering, University of Mississippi, University, Mississippi, USA
| | - David A Puleo
- Office of the Provost, The University of Alabama in Huntsville, Huntsville, Alabama, USA
| | - Thomas A Werfel
- Department of BioMolecular Sciences, University of Mississippi, University, Mississippi, USA
- Department of Biomedical Engineering, University of Mississippi, University, Mississippi, USA
- Cancer Center and Research Institute, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Department of Chemical Engineering, University of Mississippi, University, Mississippi, USA
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Ryan RS, Copello A, Fox AP. Experiences of microdosing psychedelics in an attempt to support wellbeing and mental health. BMC Psychiatry 2023; 23:160. [PMID: 36918852 PMCID: PMC10012542 DOI: 10.1186/s12888-023-04628-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 02/22/2023] [Indexed: 03/15/2023] Open
Abstract
BACKGROUND Microdosing psychedelic drugs is a growing phenomenon, but little is known about the experiences surrounding this. Research broadly suggests that people may use psychedelics in an attempt to self-medicate for mental health and wellbeing. However, the precise details, rationale and meaning of such attempts remains unclear, and would benefit from clarification, using tailored experiential methods. This research therefore aimed to explore the way that users make sense of microdosing psychedelics, with a particular focus on the experience of any perceived mental health or wellbeing changes. METHOD Participants were recruited via websites and online forums. An internet text-based, semi-structured interview was conducted anonymously with 13 participants regarding their experiences of microdosing psychedelic drugs. Interpretive Phenomenological Analysis was used to analyse the transcripts. RESULTS Three superordinate themes were identified through the interviews: 1) Seeking a solution: Agency and rationale; 2) Microdosers as scientists; 3) Catalysing desirable and beneficial effects. CONCLUSIONS All participants approached microdosing methodically and with purpose. Participants reported that they had experienced beneficial effects of microdosing on their mental health, alongside cognitive, physical and social changes. By microdosing, participants reported that they had supported their own mental health and wellbeing, with microdosing described as a catalyst to achieving their aims in this area. This study provided additional knowledge and understanding of the experience, rationale and personal meaning of the microdosing phenomenon which can be used to inform future investigations in the areas of psychedelic use and mental health.
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Affiliation(s)
- Rebecca S Ryan
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Alex Copello
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrew P Fox
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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Sayalı C, Barrett FS. The costs and benefits of psychedelics on cognition and mood. Neuron 2023; 111:614-630. [PMID: 36681076 DOI: 10.1016/j.neuron.2022.12.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/14/2022] [Accepted: 12/24/2022] [Indexed: 01/21/2023]
Abstract
Anecdotal evidence has indicated that psychedelic substances may acutely enhance creative task performance, although empirical support for this claim is mixed at best. Clinical research has shown that psychedelics might have enduring effects on mood and well-being. However, there is no neurocognitive framework that ties acute changes in cognition to long-term effects in mood. In this review, we operationalize creativity within an emerging cognitive control framework and assess the current empirical evidence of the effects of psychedelics on creativity. Next, we leverage insights about the mechanisms and computations by which other psychoactive drugs act to enhance versus impair cognition, in particular to those that act on catecholamines, the neurophysiological consequences of which are relatively well understood. Finally, we use the same framework to link the suggested psychedelic-induced improvements in creativity with enduring psychedelic-induced improvements in mood.
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Affiliation(s)
- Ceyda Sayalı
- Center for Psychedelic and Consciousness Research, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
| | - Frederick S Barrett
- Center for Psychedelic and Consciousness Research, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; Department of Psychological & Brain Sciences, Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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Glazer J, Murray CH, Nusslock R, Lee R, de Wit H. Low doses of lysergic acid diethylamide (LSD) increase reward-related brain activity. Neuropsychopharmacology 2023; 48:418-426. [PMID: 36284231 PMCID: PMC9751270 DOI: 10.1038/s41386-022-01479-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 12/26/2022]
Abstract
Renewed interest in classic psychedelics as treatments for psychiatric disorders warrants a deeper understanding of their neural mechanisms. Single, high doses of psychedelic drugs have shown promise in treating depressive disorders, perhaps by reversing deficits in reward processing in the brain. In addition, there are anecdotal reports that repeated ingestion of low doses of LSD, or "microdosing", improve mood, cognition, and feelings of wellbeing. However, the effects of low doses of classic psychedelics on reward processing have not been studied. The current study examined the effects of two single, low doses of LSD compared to placebo on measures of reward processing. Eighteen healthy adults completed three sessions in which they received placebo (LSD-0), 13 μg LSD (LSD-13) and 26 μg LSD (LSD-26) in a within-subject, double-blind design. Neural activity was recorded while participants completed the electrophysiological monetary incentive delay task. Event-related potentials were measured during feedback processing (Reward-Positivity: RewP, Feedback-P3: FB-P3, and Late-Positive Potential: LPP). Compared to placebo, LSD-13 increased RewP and LPP amplitudes for reward (vs. neutral) feedback, and LSD-13 and LSD-26 increased FB-P3 amplitudes for positive (vs. negative) feedback. These effects were unassociated with most subjective measures of drug effects. Thus, single, low doses of LSD (vs. placebo) increased three reward-related ERP components reflecting increased hedonic (RewP), motivational (FB-P3), and affective processing of feedback (LPP). These results constitute the first evidence that low doses of LSD increase reward-related brain activity in humans. These findings may have important implications for the treatment of depressive disorders.
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Affiliation(s)
- James Glazer
- Department of Psychology, Northwestern University, 2029 Sheridan Road Evanston, Chicago, IL, 60208, USA
| | - Conor H Murray
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Robin Nusslock
- Department of Psychology, Northwestern University, 2029 Sheridan Road Evanston, Chicago, IL, 60208, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
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Hartogsohn I, Petranker R. Set and setting in microdosing: an oft-overlooked principle. Psychopharmacology (Berl) 2022; 239:3771-3777. [PMID: 36289109 DOI: 10.1007/s00213-022-06249-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 09/24/2022] [Indexed: 11/24/2022]
Abstract
RATIONALE The use of psychedelics for medical and recreational purposes is rising. Contextual factors such as expectancy, intention, and sensory and social environment (set and setting) are widely recognized as moderating the effects of these substances. Nevertheless, clinical trials of microdosing - the ingestion of small, sub-hallucinogenic doses of psychedelics - rarely report their set and setting. This fact suggests that such factors are not considered important in the context of microdosing. OBJECTIVE This paper challenges this assumption and makes the case for the crucial relevance of set and setting in microdosing practice. Building on set and setting theory and placebo theory, we explain why set and setting are of crucial importance in the case of microdosing. RESULTS This reasoning helps elucidate the role of set and setting in determining the outcomes of microdosing and helps explain some of the contradictory results that have emerged in microdosing research in recent years. CONCLUSION Set and setting are important constructs to be considered especially in the context of microdosing psychedelics. By reporting set and setting, the results of microdosing research can be made more reliable and consistent.
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Affiliation(s)
- Ido Hartogsohn
- The Program for Science, Technology and Society Studies, Bar Ilan University, Ramat Gan, Israel
| | - Rotem Petranker
- Department of Psychology, McMaster University, Hamilton, ON, Canada.
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The Altered States Database: Psychometric data from a systematic literature review. Sci Data 2022; 9:720. [PMID: 36418335 PMCID: PMC9684144 DOI: 10.1038/s41597-022-01822-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 11/01/2022] [Indexed: 11/26/2022] Open
Abstract
In this paper, we present the development of the Altered States Database (ASDB), an open-science project based on a systematic literature review. The ASDB contains psychometric questionnaire data on subjective experiences of altered states of consciousness (ASC) induced by pharmacological and non-pharmacological methods. The systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Scientific journal articles were identified through PubMed and Web of Science. We included studies that examined ASC using the following validated questionnaires: Altered States of Consciousness Rating Scale (APZ, 5D-ASC, 11-ASC), Phenomenology of Consciousness Inventory (PCI), Hallucinogen Rating Scale (HRS), or Mystical Experience Questionnaire (MEQ30). The systematic review resulted in the inclusion of a total of 165 journal articles, whereof questionnaire data was extracted and is now available on the Open Science Framework (OSF) website (https://osf.io/8mbru) and on the ASDB website (http://alteredstatesdb.org), where questionnaire data can be easily retrieved and visualized. This data allows the calculation of comparable psychometric values of ASC experiences and of dose-response relationships of substances inducing ASC. Measurement(s) | Psychometric questionnaire data | Technology Type(s) | Systematic literature review (PRISMA) | Sample Characteristic - Organism | Human |
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Wong A, Raz A. Microdosing with classical psychedelics: Research trajectories and practical considerations. Transcult Psychiatry 2022; 59:675-690. [PMID: 36317302 DOI: 10.1177/13634615221129115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Microdosing-the intermittent ingestion of minute, sub-hallucinogenic amounts of psychedelic substances, repeatedly and over time-has become a widespread, albeit largely understudied, phenomenon. Regulations around using psychedelics at any dose-micro, mini, macro, or mega-pose all sorts of difficulties for those who wish to systematically study the effects of Schedule I drugs, especially in the United States. Microdosers commonly claim that taking a sub-hallucinogenic (pre-hallucinogenic or sub-perceptual) dose improves higher brain functions, including creativity, productivity, and mood. If true, these results would provide an important experimental edge in distinguishing psychosocial effects (e.g. caused by expectation) from those related to the active psychedelic ingredient. In this critical integrative synthesis, we explore the psychobiological science of dose amounts and how it informs microdosing with classical psychedelics (e.g. lysergic acid diethylamide [LSD] and psilocybin) to highlight and fuel research into questions (e.g. in cognitive neuroscience, consciousness studies, and metacognition). We sketch the hurdle-laden regulatory landscape and the procedures that shroud research with Schedule I drugs. Finally, we offer some future directions relevant to both scholars and clinicians in the social and behavioral sciences as well as in mental health and neurological science.
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Affiliation(s)
| | - Amir Raz
- 6226Chapman University, USA.,5620McGill University, Canada.,Jewish General Hospital, Canada
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Natural language signatures of psilocybin microdosing. Psychopharmacology (Berl) 2022; 239:2841-2852. [PMID: 35676541 DOI: 10.1007/s00213-022-06170-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/26/2022] [Indexed: 10/18/2022]
Abstract
RATIONALE Serotonergic psychedelics are being studied as novel treatments for mental health disorders and as facilitators of improved well-being, mental function, and creativity. Recent studies have found mixed results concerning the effects of low doses of psychedelics ("microdosing") on these domains. However, microdosing is generally investigated using instruments designed to assess larger doses of psychedelics, which might lack sensitivity and specificity for this purpose. OBJECTIVES Determine whether unconstrained speech contains signatures capable of identifying the acute effects of psilocybin microdoses. METHODS Natural speech under psilocybin microdoses (0.5 g of psilocybin mushrooms) was acquired from thirty-four healthy adult volunteers (11 females: 32.09 ± 3.53 years; 23 males: 30.87 ± 4.64 years) following a double-blind and placebo-controlled experimental design with two measurement weeks per participant. On Wednesdays and Fridays of each week, participants consumed either the active dose (psilocybin) or the placebo (edible mushrooms). Features of interest were defined based on variables known to be affected by higher doses: verbosity, semantic variability, and sentiment scores. Machine learning models were used to discriminate between conditions. Classifiers were trained and tested using stratified cross-validation to compute the AUC and p-values. RESULTS Except for semantic variability, these metrics presented significant differences between a typical active microdose and the inactive placebo condition. Machine learning classifiers were capable of distinguishing between conditions with high accuracy (AUC [Formula: see text] 0.8). CONCLUSIONS These results constitute first evidence that low doses of serotonergic psychedelics can be identified from unconstrained natural speech, with potential for widely applicable, affordable, and ecologically valid monitoring of microdosing schedules.
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Microdosing with psilocybin mushrooms: a double-blind placebo-controlled study. Transl Psychiatry 2022; 12:307. [PMID: 35918311 PMCID: PMC9346139 DOI: 10.1038/s41398-022-02039-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 06/21/2022] [Accepted: 06/29/2022] [Indexed: 12/12/2022] Open
Abstract
The use of low sub-perceptual doses of psychedelics ("microdosing") has gained popularity in recent years. Although anecdotal reports claim multiple benefits associated with this practice, the lack of placebo-controlled studies severely limits our knowledge of microdosing and its effects. Moreover, research conducted in standard laboratory settings could fail to capture the motivation of individuals engaged or planning to engage in microdosing protocols, thus underestimating the likelihood of positive effects on creativity and cognitive function. We recruited 34 individuals starting to microdose with psilocybin mushrooms (Psilocybe cubensis), one of the materials most frequently used for this purpose. Following a double-blind placebo-controlled experimental design, we investigated the acute and short-term effects of 0.5 g of dried mushrooms on subjective experience, behavior, creativity (divergent and convergent thinking), perception, cognition, and brain activity. The reported acute effects were significantly more intense for the active dose compared to the placebo, but only for participants who correctly identified their experimental condition. These changes were accompanied by reduced EEG power in the theta band, together with preserved levels of Lempel-Ziv broadband signal complexity. For all other measurements there was no effect of microdosing except for few small changes towards cognitive impairment. According to our findings, low doses of psilocybin mushrooms can result in noticeable subjective effects and altered EEG rhythms, but without evidence to support enhanced well-being, creativity and cognitive function. We conclude that expectation underlies at least some of the anecdotal benefits attributed to microdosing with psilocybin mushrooms.
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Psychedelic drugs for psychiatric disorders. J Neurol Sci 2022; 440:120332. [DOI: 10.1016/j.jns.2022.120332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 05/31/2022] [Accepted: 06/23/2022] [Indexed: 11/19/2022]
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Hartong V, van Emmerik A. Psychedelic Microdosing, Mindfulness, and Anxiety: A Cross-Sectional Mediation Study. J Psychoactive Drugs 2022:1-11. [PMID: 35694791 DOI: 10.1080/02791072.2022.2080616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
While anecdotal reports claim that psychedelic microdosing reduces anxiety and mood symptoms, evidence supporting these claims is scarce. This cross-sectional study investigated the association between microdosing and trait anxiety. Furthermore, it was investigated if trait mindfulness mediated this association. Participants completed anonymous online questionnaires and were divided into three groups: current microdosers (n = 186), former microdosers (n = 77) and microdosing-naïve controls (n = 234). Trait anxiety and trait mindfulness were measured using the State-Trait Anxiety Inventory - Trait subscale (STAI-T) and the 15-item Five-Facet Mindfulness Questionnaire (FFMQ-15) respectively. Current and former microdosers reported lower STAI-T scores compared to microdosing-naïve controls. Furthermore, associations of current and former microdosing with trait anxiety were mediated by trait mindfulness, with small effects of FFMQ-15 Total, Non-judging and Non-reactivity scores. However, in an exploratory analysis, all associations between microdosing and STAI-T scores became non-significant when participants with previous macrodose experience (n = 386) were excluded. Our findings suggest that RCT<apos;>s are warranted to test causal hypotheses concerning the effects of microdosing and the role of trait mindfulness in the effects of microdosing, while controlling for previous macrodose experience.
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Affiliation(s)
- Vincent Hartong
- Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Arnold van Emmerik
- Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam, Amsterdam, Netherlands
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Murray CH, Tare I, Perry CM, Malina M, Lee R, de Wit H. Low doses of LSD reduce broadband oscillatory power and modulate event-related potentials in healthy adults. Psychopharmacology (Berl) 2022; 239:1735-1747. [PMID: 34613430 PMCID: PMC9847217 DOI: 10.1007/s00213-021-05991-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 09/20/2021] [Indexed: 01/21/2023]
Abstract
RATIONALE Classical psychedelics, including psilocybin and lysergic acid diethylamide (LSD), are under investigation as potential therapeutic agents in psychiatry. Whereas most studies utilize relatively high doses, there are also reports of beneficial effects of "microdosing," or repeated use of very low doses of these drugs. The behavioral and neural effects of these low doses are not fully understood. OBJECTIVES To examine the effects of LSD (13 μg and 26 μg) versus placebo on resting-state electroencephalography (EEG) and event-related potential (ERP) responses in healthy adults. METHODS Twenty-two healthy men and women, 18 to 35 years old, participated in 3 EEG sessions in which they received placebo or LSD (13 μg and 26 μg) under double-blind conditions. During each session, participants completed drug effect and mood questionnaires at hourly intervals, and physiological measures were recorded. During expected peak drug effect, EEG recordings were obtained, including resting-state neural oscillations in scalp electrodes over default mode network (DMN) regions and P300, N170, and P100 ERPs evoked during a visual oddball paradigm. RESULTS LSD dose-dependently reduced oscillatory power across delta, theta, alpha, beta, and gamma frequency bands during both eyes closed and eyes open resting conditions. During the oddball task, LSD dose-dependently reduced ERP amplitudes for P300 and N170 components and increased P100 latency. LSD also produced dose-related increases in positive mood, elation, energy, and anxiety and increased heart rate and blood pressure. On a measure of altered states of consciousness, LSD dose-dependently increased Blissful State, but not other indices of perceptual or sensory effects typical of psychedelic drugs. The subjective effects of the drug were not correlated with the EEG measures. CONCLUSIONS Low doses of LSD produced broadband cortical desynchronization over the DMN during resting state and reduced P300 and N170 amplitudes, patterns similar to those reported with higher doses of psychedelics. Notably, these neurophysiological effects raise the possibility that very low doses of LSD may produce subtle behavioral and perhaps therapeutic effects that do not rely on the full psychedelic experience.
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Affiliation(s)
- Conor H Murray
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Ilaria Tare
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Claire M Perry
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Michael Malina
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave MC3077, Chicago, IL, 60637, USA.
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Vohra HZ, Saunders JM, Jaster AM, de la Fuente Revenga M, Jimenez J, Fernández-Teruel A, Wolstenholme JT, Beardsley PM, González-Maeso J. Sex-specific effects of psychedelics on prepulse inhibition of startle in 129S6/SvEv mice. Psychopharmacology (Berl) 2022; 239:1649-1664. [PMID: 34345931 PMCID: PMC10103008 DOI: 10.1007/s00213-021-05913-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/22/2021] [Indexed: 01/04/2023]
Abstract
BACKGROUND Prepulse inhibition (PPI) of startle is a sensorimotor gating phenomenon perturbed in a variety of neuropsychiatric conditions. Psychedelics disrupt PPI in rats and humans, but their effects and involvement of the serotonin 5-HT2A receptor (5-HT2AR) in mice remain unexplored. METHODS We tested the effect of the psychedelic 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (0.5 mg/kg, i.p.) on startle amplitude and %PPI in response to acoustic stimuli under up to four different experimental conditions that included changes in background and stimulus intensity, prepulse and pulse duration, and interstimulus interval in male and female 129S6/SvEv mice. We also evaluated the effect of the 5-HT2AR antagonist M100,907 (1 mg/kg, i.p.) on DOI-induced startle amplitude and %PPI, as well as the effect of the psychedelic LSD (0.24 mg/kg, i.p.) and the dopamine agonists apomorphine (5 mg/kg, s.c.) and SKF-82,958 (0.5 mg/kg, i.p.) in male 129S6/SvEv mice. RESULTS DOI altered startle amplitude with either pulse alone or prepulse + pulse presentations in all PPI conditions, and increased %PPI in three out of four PPI conditions in male mice - an effect that was prevented by M100,907. In female mice, DOI increased %PPI without affecting startle amplitude. %PPI was positively correlated with startle amplitude in males while being negatively correlated in female mice. In male mice, LSD also increased %PPI, although it did not affect startle amplitude, whereas apomorphine and SKF-82,958 induced decreases in %PPI. CONCLUSION Our findings highlight a distinct effect of the psychedelic DOI on PPI in 129S6/SvEv mice, suggesting 5-HT2AR-dependent PPI improvement in a paradigm-dependent and sex-dependent manner.
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Affiliation(s)
- Hiba Z Vohra
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Justin M Saunders
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Alaina M Jaster
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.,Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Mario de la Fuente Revenga
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.,Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Jennifer Jimenez
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Alberto Fernández-Teruel
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neurosciences, School of Medicine, Universidad Autónoma de Barcelona, E-08193, Bellaterra, Barcelona, Spain
| | - Jennifer T Wolstenholme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.,VCU Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Patrick M Beardsley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.,Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
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44
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Polito V, Liknaitzky P. The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955 - 2021) and recommendations for the field. Neurosci Biobehav Rev 2022; 139:104706. [PMID: 35609684 DOI: 10.1016/j.neubiorev.2022.104706] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 05/09/2022] [Accepted: 05/18/2022] [Indexed: 12/20/2022]
Abstract
The use of low doses of psychedelic substances (microdosing) is attracting increasing interest. This systematic review summarises all empirical microdosing research to date, including a set of infrequently cited studies that took place prior to prohibition. Specifically, we reviewed 44 studies published between 1955 and 2021, and summarised reported effects across six categories: mood and mental health; wellbeing and attitude; cognition and creativity; personality; changes in conscious state; and neurobiology and physiology. Studies showed a wide range in risk of bias, depending on design, age, and other study characteristics. Laboratory studies found changes in pain perception, time perception, conscious state, and neurophysiology. Self-report studies found changes in cognitive processing and mental health. We review data related to expectation and placebo effects, but argue that claims that microdosing effects are largely due to expectancy are premature and possibly wrong. In addition, we attempt to clarify definitional inconsistencies in the microdosing literature by providing suggested dose ranges across different substances. Finally, we provide specific design suggestions to facilitate more rigorous future research.
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Affiliation(s)
- Vince Polito
- School of Psychological Sciences, Macquarie University, Australia.
| | - Paul Liknaitzky
- Turner Institute, School of Psychological Sciences, Monash University, Australia; Department of Psychiatry, School of Clinical Sciences, Monash University, Australia.
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45
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Strickland JC, Johnson MW. Human behavioral pharmacology of psychedelics. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 93:105-132. [PMID: 35341564 DOI: 10.1016/bs.apha.2021.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The past decade has witnessed a rapid growth of research on the basic science and clinical understanding of psychedelics. This chapter provides an overview of the human behavioral pharmacology of psychedelics focusing on three prototypic classic psychedelics-psilocybin, lysergic acid diethylamide (LSD), and dimethyltryptamine (DMT). A brief historical overview of the classic psychedelics and naming and drug classification is first specified. Next, special considerations in the conduct of human behavioral pharmacology work with psychedelics is described including the role of set and setting, mystical experience measurement, the use of effective blinding and placebos, and the abuse liability of psychedelics. Following, a description of the subjective, physiological, and clinical effects of psilocybin, LSD, and DMT is provided. This body of work clearly documents a unique and complex collection of subjective effects following psychedelic use, both during acute drug administration and as related to long-term behavior change following use. Clinical research demonstrates potential therapeutic utility with early phase clinical trials showing positive and enduring effects in many difficult-to-treat conditions including treatment-resistant depression, alcohol use disorder, and cigarette smoking. Future work in this newly reemerged field is needed to reveal mechanisms of behavior change in psychedelic drug action. Behavioral pharmacology is ultimately well served to provide this direction answering questions at the intersection of environment and pharmacology.
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Affiliation(s)
- Justin C Strickland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Matthew W Johnson
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
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46
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Li H, Zhong Y, Yang S, Wang J, Li X, Xu J, Gao H, Chen G. The potential role of lysergic acid diethylamide for psychological assisted therapy: A meta-analysis of randomised controlled trials in healthy volunteers. Hum Psychopharmacol 2022; 37:e2825. [PMID: 34739739 DOI: 10.1002/hup.2825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/10/2022]
Abstract
OBJECTIVE In recent years, interest in using lysergic acid diethylamide (LSD) in psychiatric research and corresponding therapy has increased rapidly. In this meta-analysis, we explored the effects of LSD on healthy subjects with respect to subjective drug effects, blood pressure, heart rate, body temperature and side effects. METHOD PubMed, Embase, and the Cochrane Library were searched from January 2010 to December 2020 for randomized controlled trials (RCTs) on the effects of LSD in healthy people. Subsequently, 5 RCTs with 132 healthy people which focused on the effects of LSD were enrolled in our study. RESULT We found that taking 50, 100 and 200 mcg LSD doses were associated with a significant increase in the maximal difference from the baseline compared to the placebo group among the outcomes of AMRS (Adjective Mood Rating Scale) score. Significant differences existed between the LSD and placebo groups when taking 100 and 200 mcg LSD in acute adverse effects (100 mcg: SMD = .97, 95% confidence interval [CI], .50, 1.44, Z = 4.04, p < .001; 200 mcg: SMD = 1.18, 95% CI, 0.65, 1.72, Z = 4.32, p < .001). CONCLUSIONS Meta-analysis of the subjective effects of LSD in healthy people revealed moderate significant effect sizes in favor of LSD with no significant adverse effects. A 100 mcg dose of LSD has potential for use in psychological-assisted therapy and may improve the mental fitness of patients with disease-related psychiatric distress. Additional clinical trials are necessary to explore the efficacy and safety of LSD as a psychological-assisted therapy.
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Affiliation(s)
- Hang Li
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Yi Zhong
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Siyuan Yang
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Jiahe Wang
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Xiang Li
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Jianguo Xu
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Heng Gao
- Department of Clinical Medicine, The Affiliated Jiangyin Hospital, School of Medicine, Southeast University, Jiangyin, Jiangsu Province, China
| | - Gang Chen
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
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Wießner I, Olivieri R, Falchi M, Palhano-Fontes F, Oliveira Maia L, Feilding A, B Araujo D, Ribeiro S, Tófoli LF. LSD, afterglow and hangover: Increased episodic memory and verbal fluency, decreased cognitive flexibility. Eur Neuropsychopharmacol 2022; 58:7-19. [PMID: 35158230 DOI: 10.1016/j.euroneuro.2022.01.114] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/26/2022] [Accepted: 01/29/2022] [Indexed: 12/20/2022]
Abstract
Psychedelics acutely impair cognitive functions, but these impairments decline with growing experiences with psychedelics and microdoses may even exert opposing effects. Given the recent evidence that psychedelics induce neuroplasticity, this explorative study aimed at investigating the potential of psychedelics to sub-acutely change cognition. For this, we applied a randomized, double-blind, placebo-controlled, crossover study with 24 healthy volunteers receiving 50 μg lysergic acid diethylamide (LSD) or an inactive placebo. Sub-acute changes in cognition were measured 24 h after dosing, including memory (Rey-Osterrieth Complex Figure, ROCF; 2D Object-Location Memory Task, OLMT; Rey Auditory-Verbal Learning Test, RAVLT), verbal fluency (phonological; semantic; switch), design fluency (basic; filter; switch), cognitive flexibility (Wisconsin Card Sorting Test, WCST), sustained and switching attention (Trail Making Test, TMT), inhibitory control (Stroop Task) and perceptual reasoning (Block Design Test, BDT). The results show that when compared to placebo and corrected for Body Mass Index (BMI) and abstinence period from psychedelics, LSD sub-acutely improved visuospatial memory (ROCF immediate recall points and percentage, OLMT consolidation percentage) and phonological verbal fluency and impaired cognitive flexibility (WCST: fewer categories achieved; more perseveration, errors and conceptual level responses). In conclusion, the low dose of LSD moderately induced both "afterglow" and "hangover". The improvements in visuospatial memory and phonological fluency suggest that LSD-assisted therapy should be explored as a novel treatment perspective in conditions involving memory and language declines such as brain injury, stroke or dementia.
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Affiliation(s)
- Isabel Wießner
- Department of Psychiatry, School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil.
| | - Rodolfo Olivieri
- Department of Psychiatry, School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
| | - Marcelo Falchi
- Department of Psychiatry, School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
| | - Fernanda Palhano-Fontes
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Lucas Oliveira Maia
- Department of Psychiatry, School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
| | - Amanda Feilding
- The Beckley Foundation, Beckley Park, Oxford, United Kingdom
| | - Draulio B Araujo
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Sidarta Ribeiro
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Luís Fernando Tófoli
- Department of Psychiatry, School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil
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48
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Bălăeţ M. Psychedelic Cognition—The Unreached Frontier of Psychedelic Science. Front Neurosci 2022; 16:832375. [PMID: 35401088 PMCID: PMC8989050 DOI: 10.3389/fnins.2022.832375] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/27/2022] [Indexed: 12/14/2022] Open
Abstract
Psychedelic compounds hold the promise of changing the face of neuroscience and psychiatry as we know it. There have been numerous proposals to use them to treat a range of neuropsychiatric conditions such as depression, anxiety, addiction and PTSD; and trials to date have delivered positive results in favor of the novel therapeutics. Further to the medical use, the wider healthy population is gaining interest in these compounds. We see a surge in personal use of psychedelic drugs for reasons not limited to spiritual enhancement, improved productivity, aiding the management of non-pathological anxiety and depression, and recreational interests. Notably, microdosing—the practice of taking subacute doses of psychedelic compounds—is on the rise. Our knowledge about the effects of psychedelic compounds, however, especially in naturalistic settings, is still fairly limited. In particular, one of the largest gaps concerns the acute effects on cognition caused by psychedelics. Studies carried out to date are riddled with limitations such as having disparate paradigms, small sample sizes, and insufficient breadth of testing on both unhealthy and healthy volunteers. Moreover, the studies are majoritarily limited to laboratory settings and do not assess the effects at multiple dosages within the same paradigm nor at various points throughout the psychedelic experience. This review aims to summarize the studies to date in relation to how psychedelics acutely affect different domains of cognition. In the pursuit of illuminating the current limitations and offering long-term, forward-thinking solutions, this review compares and contrasts findings related to how psychedelics impact memory, attention, reasoning, social cognition, and creativity.
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49
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Wit H, Molla HM, Bershad A, Bremmer M, Lee R. Repeated low doses of LSD in healthy adults: A placebo-controlled, dose-response study. Addict Biol 2022; 27:e13143. [PMID: 35106880 DOI: 10.1111/adb.13143] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/11/2021] [Accepted: 12/21/2021] [Indexed: 12/17/2022]
Abstract
The resurgence of interest in using psychedelic drugs, including lysergic acid diethylamide (LSD), in psychiatry has drawn attention to the medically unsupervised practice of 'microdosing'. Thousands of users claim that very low doses of LSD, taken at 3-4-day intervals, improve mood and cognitive function., However, few controlled studies have described the effects of the drug when taken in this way. Here, in a double-blind controlled study, we studied the effects of four repeated doses of LSD tartrate (13 or 26 μg) or placebo, administered to healthy adults at 3-4 day intervals, on mood, cognitive performance and responses to emotional tasks. Participants were randomly assigned to one of three drug conditions: placebo (N = 18), 13 μg LSD (N = 19), or 26 μg LSD (N = 19). They attended four 5-hour drug-administration sessions separated by 3-4 days, followed by a drug-free follow-up session 3-4 days after the last session. LSD (26 μg) produced modest subjective effects including increased ratings of 'feeling a drug effect' and both stimulant-like and LSD-like effects, but the drug did not improve mood or affect performance on psychomotor or most emotional tasks. No residual effects were detected on mood or task performance on the drug-free follow-up session. We conclude that within the context of a controlled setting and a limited number of administrations, repeated low doses of LSD are safe, but produce negligible changes in mood or cognition in healthy volunteers.
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Affiliation(s)
- Harriet Wit
- Department of Psychiatry and Behavioral Neuroscience University of Chicago Chicago Illinois USA
| | - Hanna M. Molla
- Department of Psychiatry and Behavioral Neuroscience University of Chicago Chicago Illinois USA
| | - Anya Bershad
- Semel Institute for Neuroscience and Human Behavior University of California at Los Angeles Los Angeles California USA
| | - Michael Bremmer
- Department of Psychiatry and Behavioral Neuroscience University of Chicago Chicago Illinois USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience University of Chicago Chicago Illinois USA
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50
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Markopoulos A, Inserra A, De Gregorio D, Gobbi G. Evaluating the Potential Use of Serotonergic Psychedelics in Autism Spectrum Disorder. Front Pharmacol 2022; 12:749068. [PMID: 35177979 PMCID: PMC8846292 DOI: 10.3389/fphar.2021.749068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/04/2021] [Indexed: 01/29/2023] Open
Abstract
Recent clinical and preclinical evidence points towards empathogenic and prosocial effects elicited by psychedelic compounds, notably the serotonin 5-HT2A agonists lysergic acid diethylamide (LSD), psilocybin, N,N-Dimethyltryptamine (DMT), and their derivatives. These findings suggest a therapeutic potential of psychedelic compounds for some of the behavioural traits associated with autism spectrum disorder (ASD), a neurodevelopmental condition characterized by atypical social behaviour. In this review, we highlight evidence suggesting that psychedelics may potentially ameliorate some of the behavioural atypicalities of ASD, including reduced social behaviour and highly co-occurring anxiety and depression. Next, we discuss dysregulated neurobiological systems in ASD and how they may underlie or potentially limit the therapeutic effects of psychedelics. These phenomena include: 1) synaptic function, 2) serotonergic signaling, 3) prefrontal cortex activity, and 4) thalamocortical signaling. Lastly, we discuss clinical studies from the 1960s and 70s that assessed the use of psychedelics in the treatment of children with ASD. We highlight the positive behavioural outcomes of these studies, including enhanced mood and social behaviour, as well as the adverse effects of these trials, including increases in aggressive behaviour and dissociative and psychotic states. Despite preliminary evidence, further studies are needed to determine whether the benefits of psychedelic treatment in ASD outweigh the risks associated with the use of these compounds in this population, and if the 5-HT2A receptor may represent a target for social-behavioural disorders.
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Affiliation(s)
- Athanasios Markopoulos
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada.,McGill University Health Centre, McGill University, Montreal, QC, Canada
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