1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Korkmaz ND, Cikrikcili U, Akan M, Yucesan E. Psychedelic therapy in depression and substance use disorders. Eur J Neurosci 2024; 60:4063-4077. [PMID: 38773750 DOI: 10.1111/ejn.16421] [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: 02/15/2024] [Revised: 04/20/2024] [Accepted: 05/05/2024] [Indexed: 05/24/2024]
Abstract
Psychoactive substances obtained from botanicals have been applied for a wide variety of purposes in the rituals of different cultures for thousands of years. Classical psychedelics from N,N'-dimethyltryptamine, psilocybin, mescaline and various lysergamides cause specific alterations in perception, emotion and cognition by acting through serotonin 5-HT2A receptor activation. Lysergic acid diethylamide, the first famous breakthrough in the field, was discovered by chance by Albert Hoffman in the Zurich Sandoz laboratory in 1943, and studies on its psychoactive effects began to take place in the literature. Studies in this area were blocked after the legislation controlling the use and research of psychedelic drugs came into force in 1967, but since the 1990s, it has started to be a matter of scientific curiosity again by various research groups. In particular, with the crucial reports of psychotherapy-assisted psilocybin applications for life-threatening cancer-related anxiety and depression, a new avenues have been opened in the treatment of psychiatric diseases such as treatment-resistant depression and substance addictions. An increasing number of studies show that psychedelics have a very promising potential in the treatment of neuropsychiatric diseases where the desired efficiency cannot be achieved with conventional treatment methods. In this context, we discuss psychedelic therapy, encompassing its historical development, therapeutic applications and potential treatment effects-especially in depression, trauma disorders and substance use disorders-within the framework of ethical considerations.
Collapse
Affiliation(s)
- Nur Damla Korkmaz
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
- Graduate School of Health Sciences, Istanbul University, Istanbul, Turkey
- Department of Medical Biology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Ugur Cikrikcili
- Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University, Magdeburg, Germany
- Deutsche Zentrum für Neurodegenerative Erkrankungen (DZNE), Magdeburg, Germany
| | - Merve Akan
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Emrah Yucesan
- Institute of Neurological Sciences, Department of Neurogenetics, Istanbul University-Cerrahpasa, Istanbul, Turkey
| |
Collapse
|
3
|
Polito V, Liknaitzky P. Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research. J Psychopharmacol 2024:2698811241254831. [PMID: 38877715 DOI: 10.1177/02698811241254831] [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: 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.
Collapse
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
| |
Collapse
|
4
|
Szigeti B, Weiss B, Rosas FE, Erritzoe D, Nutt D, Carhart-Harris R. Assessing expectancy and suggestibility in a trial of escitalopram v. psilocybin for depression. Psychol Med 2024; 54:1717-1724. [PMID: 38247730 DOI: 10.1017/s0033291723003653] [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: 01/23/2024]
Abstract
BACKGROUND To investigate the association between pre-trial expectancy, suggestibility, and response to treatment in a trial of escitalopram and investigational drug, COMP360, psilocybin, in the treatment of major depressive disorder (ClinicalTrials.gov registration: NCT03429075). METHODS We used data (n = 55) from our recent double-blind, parallel-group, randomized head-to-head comparison trial of escitalopram and investigational drug, COMP360, psilocybin. Mixed linear models were used to investigate the association between pre-treatment efficacy-related expectations, as well as baseline trait suggestibility and absorption, and therapeutic response to both escitalopram and COMP360 psilocybin. RESULTS Patients had significantly higher expectancy for psilocybin relative to escitalopram; however, expectancy for escitalopram was associated with improved therapeutic outcomes to escitalopram, expectancy for psilocybin was not predictive of response to psilocybin. Separately, we found that pre-treatment trait suggestibility was associated with therapeutic response in the psilocybin arm, but not in the escitalopram arm. CONCLUSIONS Overall, our results suggest that psychedelic therapy may be less vulnerable to expectancy biases than previously suspected. The relationship between baseline trait suggestibility and response to psilocybin therapy implies that highly suggestible individuals may be primed for response to this treatment.
Collapse
Affiliation(s)
- Balázs Szigeti
- Centre for Psychedelic Research, Imperial College London, UK
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, USA
| | - Brandon Weiss
- Centre for Psychedelic Research, Imperial College London, UK
| | - Fernando E Rosas
- Centre for Psychedelic Research, Imperial College London, UK
- Centre for Complexity Science, Imperial College London, UK
- Department of Informatics, University of Sussex, Brighton, UK
- Centre for Eudaimonia and Human Flourishing, University of Oxford, Oxford, UK
| | - David Erritzoe
- Centre for Psychedelic Research, Imperial College London, UK
| | - David Nutt
- Centre for Psychedelic Research, Imperial College London, UK
| | - Robin Carhart-Harris
- Depts. of Neurology, Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, USA
| |
Collapse
|
5
|
Szigeti B, Heifets BD. Expectancy Effects in Psychedelic Trials. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:512-521. [PMID: 38387698 DOI: 10.1016/j.bpsc.2024.02.004] [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: 10/18/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
Clinical trials of psychedelic compounds like psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltrptamine (DMT) have forced a reconsideration of how nondrug factors, such as participant expectations, are measured and controlled in mental health research. As doses of these profoundly psychoactive substances increase, so does the difficulty in concealing the treatment condition in the classic double-blind, placebo-controlled trial design. As widespread public enthusiasm for the promise of psychedelic therapy grows, so do questions regarding whether and how much trial results are biased by positive expectancy. First, we review the key concepts related to expectancy and its measurement. Then, we review expectancy effects that have been reported in both micro- and macrodose psychedelic trials from the modern era. Finally, we consider expectancy as a discrete physiological process that can be independent of, or even interact with, the drug effect. Expectancy effects can be harnessed to improve treatment outcomes and can also be actively managed in controlled studies to enhance the rigor and generalizability of future psychedelic trials.
Collapse
Affiliation(s)
- Balázs Szigeti
- Translational Psychedelic Research Program, University of California San Francisco, San Francisco, California; Centre for Psychedelic Research, Imperial College London, London, UK
| | - Boris D Heifets
- Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California.
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
Barksdale BR, Doss MK, Fonzo GA, Nemeroff CB. The mechanistic divide in psychedelic neuroscience: An unbridgeable gap? Neurotherapeutics 2024; 21:e00322. [PMID: 38278658 DOI: 10.1016/j.neurot.2024.e00322] [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: 10/30/2023] [Revised: 01/10/2024] [Accepted: 01/10/2024] [Indexed: 01/28/2024] Open
Abstract
In recent years, psychedelics have generated considerable excitement and interest as potential novel therapeutics for an array of conditions, with the most advanced evidence base in the treatment of certain severe and/or treatment-resistant psychiatric disorders. An array of clinical and pre-clinical evidence has informed our current understanding of how psychedelics produce profound alterations in consciousness. Mechanisms of psychedelic action include receptor binding and downstream cellular and transcriptional pathways, with long-term impacts on brain structure and function-from the level of single neurons to large-scale circuits. In this perspective, we first briefly review and synthesize separate lines of research on potential mechanistic processes underlying the acute and long-term effects of psychedelic compounds, with a particular emphasis on highlighting current theoretical models of psychedelic drug action and their relationships to therapeutic benefits for psychiatric and brain-based disorders. We then highlight an existing area of ongoing controversy we argue is directly informed by theoretical models originating from disparate levels of inquiry, and we ultimately converge on the notion that bridging the current chasm in explanatory models of psychedelic drug action across levels of inquiry (molecular, cellular, circuit, and psychological/behavioral) through innovative methods and collaborative efforts will ultimately yield the comprehensive understanding needed to fully capitalize on the potential therapeutic properties of these compounds.
Collapse
Affiliation(s)
- Bryan R Barksdale
- Center for Psychedelic Research and Therapy, Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA
| | - Manoj K Doss
- Center for Psychedelic Research and Therapy, Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA
| | - Gregory A Fonzo
- Center for Psychedelic Research and Therapy, Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA
| | - Charles B Nemeroff
- Center for Psychedelic Research and Therapy, Department of Psychiatry and Behavioral Sciences, The University of Texas at Austin Dell Medical School, Austin, TX, USA.
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Murphy RJ, Godfrey K, Shaw AD, Muthukumaraswamy S, Sumner RL. Modulation of long-term potentiation following microdoses of LSD captured by thalamo-cortical modelling in a randomised, controlled trial. BMC Neurosci 2024; 25:7. [PMID: 38317077 PMCID: PMC10845757 DOI: 10.1186/s12868-024-00844-5] [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: 10/13/2023] [Accepted: 01/10/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Microdosing psychedelics is a phenomenon with claimed cognitive benefits that are relatively untested clinically. Pre-clinically, psychedelics have demonstrated enhancing effects on neuroplasticity, which cannot be measured directly in humans, but may be indexed by non-invasive electroencephalography (EEG) paradigms. This study used a visual long-term potentiation (LTP) EEG paradigm to test the effects of microdosed lysergic acid diethylamide (LSD) on neural plasticity, both acutely while on the drug and cumulatively after microdosing every third day for six weeks. Healthy adult males (n = 80) completed the visual LTP paradigm at baseline, 2.5 h following a dose of 10 µg of LSD or inactive placebo, and 6 weeks later after taking 14 repeated microdoses. Visually induced LTP was used as indirect index of neural plasticity. Surface level event-related potential (ERPs) based analyses are presented alongside dynamic causal modelling of the source localised data using a generative thalamocortical model (TCM) of visual cortex to elucidate underlying synaptic circuitry. RESULTS Event-related potential (ERP) analyses of N1b and P2 components did not show evidence of changes in visually induced LTP by LSD either acutely or after 6 weeks of regular dosing. However modelling the complete timecourse of the ERP with the TCM demonstrated changes in laminar connectivity in primary visual cortex. This primarily included changes to self-gain and inhibitory input parameters acutely. Layer 2/3 to layer 5 excitatory connectivity was also different between LSD and placebo groups. After regular dosing only excitatory input from layer 2/3 into layer 5 and inhibitory input into layer 4 were different between groups. CONCLUSIONS Without modulation of the ERPs it is difficult to relate the findings to other studies visually inducing LTP. It also indicates the classic peak analysis may not be sensitive enough to demonstrate evidence for changes in LTP plasticity in humans at such low doses. The TCM provides a more sensitive approach to assessing changes to plasticity as differences in plasticity mediated laminar connectivity were found between the LSD and placebo groups. TRIAL REGISTRATION ANZCTR registration number ACTRN12621000436875; Registered 16/04/2021 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381476 .
Collapse
Affiliation(s)
- Robin J Murphy
- School of Pharmacy, University of Auckland, Auckland, New Zealand.
| | - Kate Godfrey
- Centre for Psychedelic Research, Department of Psychiatry, Imperial College London, London, UK
| | | | | | - Rachael L Sumner
- School of Pharmacy, University of Auckland, Auckland, New Zealand
| |
Collapse
|
12
|
Miller E, Bojovic V, Maddren O, Rao P, Adesina D, Petrenko A, Ponton R. Psychedelic Drug Microdosing Practices: A Qualitative Online Exploration. J Psychoactive Drugs 2024:1-10. [PMID: 38247351 DOI: 10.1080/02791072.2024.2304554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 12/12/2023] [Indexed: 01/23/2024]
Abstract
"Microdosing," defined as the consumption of small, sub-hallucinogenic quantities of psychedelic drugs, has gained recent popularity. Microdosing is a relatively new concept, therefore no scientific recommendations exist on how to prepare and consume microdoses. Many consumers obtain microdosing information online. Few studies have investigated the content of this information; thus, the present study aimed to do so by collecting a large set of online microdosing information. A qualitative approach was taken to compile and characterize online microdosing information. Medical databases, video websites, online forums, drug-specific websites and forums, search engines, and social media websites were searched. A total of 174 unique resources were found, detailing the types of substances, preparation methods, doses, schedules, and safety strategies used by people who microdose. Future research is recommended to further explore how people prepare microdoses through in-person interviews and sample collection.
Collapse
Affiliation(s)
- Estelle Miller
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Vida Bojovic
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Olivia Maddren
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Prashant Rao
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Dami Adesina
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Anastasia Petrenko
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Rhys Ponton
- Faculty of Medical and Health Sciences, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
13
|
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.
Collapse
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.
| |
Collapse
|
14
|
Nutt DJ, Peill JM, Weiss B, Godfrey K, Carhart-Harris RL, Erritzoe D. Psilocybin and Other Classic Psychedelics in Depression. Curr Top Behav Neurosci 2023. [PMID: 37955822 DOI: 10.1007/7854_2023_451] [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: 11/14/2023]
Abstract
Psychedelic drugs such as psilocybin and ketamine are returning to clinical research and intervention across several disorders including the treatment of depression. This chapter focusses on psychedelics that specifically target the 5-HT2A receptor such as psilocybin and DMT. These produce plasma-concentration related psychological effects such as hallucinations and out of body experiences, insightful and emotional breakthroughs as well as mystical-type experiences. When coupled with psychological support, effects can produce a rapid improvement in mood among people with depression that can last for months. In this chapter, we summarise the scientific studies to date that explore the use of psychedelics in depressed individuals, highlighting key clinical, psychological and neuroimaging features of psychedelics that may account for their therapeutic effects. These include alterations in brain entropy that disrupt fixed negative ruminations, a period of post-treatment increased cognitive flexibility, and changes in self-referential psychological processes. Finally, we propose that the brain mechanisms underlying the therapeutic effect of serotonergic psychedelics might be distinct from those underlying classical serotonin reuptake-blocking antidepressants.
Collapse
Affiliation(s)
- D J Nutt
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK.
| | - J M Peill
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - B Weiss
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - K Godfrey
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - R L Carhart-Harris
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
- Psychedelics Division, Neuroscape, University of California San Francisco, San Francisco, CA, USA
| | - D Erritzoe
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| |
Collapse
|
15
|
Kruger DJ, Barron J, Herberholz M, Boehnke KF. Preferences and Support for Psychedelic Policies and Practices Among Those Using Psychedelics. J Psychoactive Drugs 2023; 55:650-659. [PMID: 37353935 DOI: 10.1080/02791072.2023.2228784] [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: 02/21/2023] [Revised: 06/11/2023] [Accepted: 05/26/2023] [Indexed: 06/25/2023]
Abstract
Legal, scientific, and social landscapes for psychedelics are changing rapidly. Differences of opinion exist among key stakeholders regarding regulatory control, models of provisioning psychedelic therapy, and medicalization, decriminalization, and/or legalization policies. We assessed the policy preferences of people using psychedelics naturalistically (N = 1221) to understand how they aligned and differed with institutional entities and existing psychedelic policies. Three quarters of participants would support decriminalization and legalization. On average, participants strongly supported individuals being legally able to grow and possess psychedelic plants and/or fungi for personal consumption. Trends included more support for natural over synthetic substances, self-production and consumption over gifting, gifting over sales, and administration of psychedelics with therapeutic support than without therapeutic support. Participants were concerned about pharmaceutical-like policy models, including patents of natural and synthetic psychedelic compounds. Participants were mostly from the State of Michigan, though geographical differences were minor. Those who identified as a psychedelic guide, educator, or therapist had small yet extensive differences from those who did not. As psychedelic liberalization continues to advance, it is critical for policymakers to consider these preferences to ensure laws provide safe and equitable access to these substances and appropriate medical support for their use.
Collapse
Affiliation(s)
- Daniel J Kruger
- Population Studies Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, USA
- Anesthesiology Department and Chronic Pain and Fatigue Research Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Julie Barron
- Blue Sage Health Consulting, Ann Arbor, MI, USA
- Michigan Psychedelic Society, Ann Arbor, MI, USA
- Decriminalize Nature, Michigan, Ann Arbor, MI, USA
| | - Moss Herberholz
- Michigan Psychedelic Society, Ann Arbor, MI, USA
- The Radical Well-Being Center, Southfield, MI, USA
| | - Kevin F Boehnke
- Anesthesiology Department and Chronic Pain and Fatigue Research Center, University of Michigan Medical School, Ann Arbor, MI, USA
| |
Collapse
|
16
|
Rahbarnia A, Li Z, Fletcher PJ. Effects of psilocybin, the 5-HT 2A receptor agonist TCB-2, and the 5-HT 2A receptor antagonist M100907 on visual attention in male mice in the continuous performance test. Psychopharmacology (Berl) 2023:10.1007/s00213-023-06474-9. [PMID: 37855864 DOI: 10.1007/s00213-023-06474-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/25/2023] [Indexed: 10/20/2023]
Abstract
RATIONALE Neuropsychiatric disorders such as depression are characterized in part by attention deficits. Attention is modulated by the serotonin (5-HT) neurotransmitter system. The 5-HT2A agonist and hallucinogen psilocybin (PSI) is a promising treatment for disorders characterized by attention changes. However, few studies have investigated PSI's direct effect on attention. OBJECTIVE Using the rodent continuous performance task (CPT), we assessed PSI's effect on attention. We also evaluated the impact of 5-HT2A receptor agonist TCB-2 and antagonist M100907 for comparative purposes. METHODS In the CPT, mice learned to distinguish visual targets from non-targets for milkshake reward. Performance was then tested following injections of PSI (0.3, 1, and 3 mg/kg), TCB-2 (0.3, 1, and 3 mg/kg), or M100907 (0.1, 0.3, and 1 mg/kg). Subsequently, drug effects were then evaluated using a more difficult CPT with variable stimulus durations. Mice were then tested on the CPT following repeated PSI injections. Drug effects on locomotor activity were also measured. RESULTS In the CPT, all three drugs reduced hit and false alarm rate and induced conservative responding. PSI also reduced target discrimination. These effects were seen primarily at doses that also significantly reduced locomotor activity. No drug effects were seen on the more difficult CPT or following repeated PSI injections. CONCLUSIONS Psilocybin, TCB-2, and M100907 impaired performance of the CPT. However, this may be in part due to drug-induced locomotor changes. The results provide little support for the idea that psilocybin alters visual attention, or that 5-HT2A receptors modulate this process.
Collapse
Affiliation(s)
- Arya Rahbarnia
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.
- Department of Psychology, University of Toronto, Toronto, ON, Canada.
| | - Zhaoxia Li
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Paul J Fletcher
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
17
|
Haijen ECHM, Hurks PPM, Kuypers KPC. Trait mindfulness and personality characteristics in a microdosing ADHD sample: a naturalistic prospective survey study. Front Psychiatry 2023; 14:1233585. [PMID: 37915796 PMCID: PMC10617390 DOI: 10.3389/fpsyt.2023.1233585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/02/2023] [Indexed: 11/03/2023] Open
Abstract
Background Microdosing (MD), repeatedly taking psychedelics in small, non-hallucinogenic amounts, has been practiced by individuals to relieve attention deficit hyperactivity disorder (ADHD) symptoms. Generally, adults diagnosed with ADHD have lower levels of mindfulness and differ in personality structure from non-ADHD adults. How MD affects mindfulness and personality in adults with ADHD remains unexplored. Aim This study aimed to investigate the effects of 4 weeks of MD on mindfulness and personality traits in adults diagnosed with ADHD and those experiencing severe ADHD symptoms. It was expected that mindfulness and the personality traits conscientiousness, extraversion, agreeableness, and openness would increase and neuroticism would decrease after 4 weeks of MD compared to baseline. It was explored if using conventional ADHD medication alongside MD and/or having comorbidities influenced MD-induced effects. Methods An online prospective naturalistic design was used to measure participants before MD initiation and 2 and 4 weeks later. Validated self-report measures were used assessing mindfulness (15-item Five Facet Mindfulness Questionnaire) and personality traits (10-item version of the Big Five Inventory) at three time points. Results The sample included n = 233, n = 66, and n = 44 participants at the three time points, respectively. Trait mindfulness, specifically description and non-judging of inner experience, was increased, and neuroticism was decreased after 4 weeks of MD compared to baseline. The remaining personality traits remained unchanged. Using conventional medication and/or having comorbid diagnoses did not change the MD-induced effects on mindfulness and personality traits after 4 weeks. Conclusion MD induced changes in otherwise stable traits. Future placebo-controlled studies are warranted to confirm whether these changes occur in a controlled setting.
Collapse
Affiliation(s)
- Eline C. H. M. Haijen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | | | | |
Collapse
|
18
|
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.
Collapse
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.
| |
Collapse
|
19
|
Ko K, Carter B, Cleare AJ, Rucker JJ. Predicting the Intensity of Psychedelic-Induced Mystical and Challenging Experience in a Healthy Population: An Exploratory Post-Hoc Analysis. Neuropsychiatr Dis Treat 2023; 19:2105-2113. [PMID: 37818448 PMCID: PMC10561760 DOI: 10.2147/ndt.s426193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/23/2023] [Indexed: 10/12/2023] Open
Abstract
Introduction In psychedelic therapy, mystical as well as challenging experience may influence therapeutic outcome. However, predictors of such experience have not been sufficiently established. Determining predictors of their intensity is, therefore, potentially beneficial in targeting psilocybin therapy for depression. Methods In a post hoc data analysis of a Phase 1, randomised, double-blind, placebo-controlled, between-groups clinical trial, dosage, personality traits, affect, and individual data were analysed as possible clinical predictors. Eighty-nine healthy volunteers were randomised to receive a single dose of placebo, 10 mg of psilocybin, or 25 mg of psilocybin. ANOVA was used to analyse the relationship between dosage and mystical and/or challenging experience, and correlation analysis for all other variables. Results The intensity of both mystical and challenging experience was strongly associated with higher dosage. Age was negatively correlated with intensity of challenging experience. Correlation between identified personality traits and either mystical or challenging experience was minimal, with the exception of positive correlation between neuroticism and challenging experience at higher dose. Neither positive nor negative affect indicated correlation with the intensity of either type of experience. Discussion A limitation of this study is its post hoc, exploratory design; recommendations for further research are provided.
Collapse
Affiliation(s)
- Kwonmok Ko
- Centre for Affective Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, SE5 8AF, UK
| | - Ben Carter
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, SE5 8AF, UK
| | - Anthony J Cleare
- Centre for Affective Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, SE5 8AF, UK
- South London and Maudsley NHS Foundation Trust, Bethlem Royal Hospital, Beckenham, BR3 3BX, UK
| | - James J Rucker
- Centre for Affective Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, SE5 8AF, UK
- South London and Maudsley NHS Foundation Trust, Bethlem Royal Hospital, Beckenham, BR3 3BX, UK
| |
Collapse
|
20
|
Amoruso E, Terhune DB, Kromm M, Kirker S, Muret D, Makin TR. Reassessing referral of touch following peripheral deafferentation: The role of contextual bias. Cortex 2023; 167:167-177. [PMID: 37567052 PMCID: PMC11139647 DOI: 10.1016/j.cortex.2023.04.019] [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: 06/20/2022] [Revised: 01/28/2023] [Accepted: 04/21/2023] [Indexed: 08/13/2023]
Abstract
Some amputees have been famously reported to perceive facial touch as arising from their phantom hand. These referred sensations have since been replicated across multiple neurological disorders and were classically interpreted as a perceptual correlate of cortical plasticity. Common to all these and related studies is that participants might have been influenced in their self-reports by the experimental design or related contextual biases. Here, we investigated whether referred sensations reports might be confounded by demand characteristics (e.g., compliance, expectation, suggestion). Unilateral upper-limb amputees (N = 18), congenital one-handers (N = 19), and two-handers (N = 22) were repeatedly stimulated with computer-controlled vibrations on 10 body-parts and asked to report the occurrence of any concurrent sensations on their hand(s). To further manipulate expectations, we gave participants the suggestion that some of these vibrations had a higher probability to evoke referred sensations. We also assessed similarity between (phantom) hand and face representation in primary somatosensory cortex (S1), using functional Magnetic Resonance Imaging (fMRI) multivariate representational similarity analysis. We replicated robust reports of referred sensations in amputees towards their phantom hand; however, the frequency and distribution of reported referred sensations were similar across groups. Moreover, referred sensations were evoked by stimulation of multiple body-parts and similarly reported on both the intact and phantom hand in amputees. Face-to-phantom-hand representational similarity was not different in amputees' missing hand region, compared with controls. These findings weaken the interpretation of referred sensations as a perceptual correlate of S1 plasticity and reveal the need to account for contextual biases when evaluating anomalous perceptual phenomena.
Collapse
Affiliation(s)
- Elena Amoruso
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK
| | - Devin B Terhune
- Department of Psychology, Goldsmiths, University of London, London SE14 6NW, UK
| | - Maria Kromm
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK
| | - Stephen Kirker
- Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Dollyane Muret
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK.
| | - Tamar R Makin
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3AR, UK
| |
Collapse
|
21
|
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.
Collapse
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.
| |
Collapse
|
22
|
Bershad AK. Psychedelic Microdosing: What Is It Good For? Biol Psychiatry 2023; 94:e23-e24. [PMID: 37611985 DOI: 10.1016/j.biopsych.2023.06.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 08/25/2023]
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, California.
| |
Collapse
|
23
|
Kiilerich KF, Lorenz J, Scharff MB, Speth N, Brandt TG, Czurylo J, Xiong M, Jessen NS, Casado-Sainz A, Shalgunov V, Kjaerby C, Satała G, Bojarski AJ, Jensen AA, Herth MM, Cumming P, Overgaard A, Palner M. Repeated low doses of psilocybin increase resilience to stress, lower compulsive actions, and strengthen cortical connections to the paraventricular thalamic nucleus in rats. Mol Psychiatry 2023; 28:3829-3841. [PMID: 37783788 DOI: 10.1038/s41380-023-02280-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 10/04/2023]
Abstract
Psilocybin (a classic serotonergic psychedelic drug) has received appraisal for use in psychedelic-assisted therapy of several psychiatric disorders. A less explored topic concerns the use of repeated low doses of psychedelics, at a dose that is well below the psychedelic dose used in psychedelic-assisted therapy and often referred to as microdosing. Psilocybin microdose users frequently report increases in mental health, yet such reports are often highly biased and vulnerable to placebo effects. Here we establish and validate a psilocybin microdose-like regimen in rats with repeated low doses of psilocybin administration at a dose derived from occupancy at rat brain 5-HT2A receptors in vivo. The rats tolerated the repeated low doses of psilocybin well and did not manifest signs of anhedonia, anxiety, or altered locomotor activity. There were no deficits in pre-pulse inhibition of the startle reflex, nor did the treatment downregulate or desensitize the 5-HT2A receptors. However, the repeated low doses of psilocybin imparted resilience against the stress of multiple subcutaneous injections, and reduced the frequency of self-grooming, a proxy for human compulsive actions, while also increasing 5-HT7 receptor expression and synaptic density in the paraventricular nucleus of the thalamus. These results establish a well-validated regimen for further experiments probing the effects of repeated low doses of psilocybin. Results further substantiate anecdotal reports of the benefits of psilocybin microdosing as a therapeutic intervention, while pointing to a possible physiological mechanism.
Collapse
Affiliation(s)
- Kat F Kiilerich
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Joe Lorenz
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Malthe B Scharff
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Nikolaj Speth
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Tobias G Brandt
- Clinical Physiology and Nuclear Medicine, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Julia Czurylo
- Clinical Physiology and Nuclear Medicine, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Mengfei Xiong
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Naja S Jessen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Clinical Physiology and Nuclear Medicine, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Agata Casado-Sainz
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Copenhagen, Denmark
| | - Celia Kjaerby
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Grzegorz Satała
- Department of Medicinal Chemistry, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Andrzej J Bojarski
- Department of Medicinal Chemistry, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Matthias M Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Copenhagen, Denmark
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, Bern, Switzerland
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Agnete Overgaard
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Mikael Palner
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.
- Clinical Physiology and Nuclear Medicine, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark.
| |
Collapse
|
24
|
Sharma P, Nguyen QA, Matthews SJ, Carpenter E, Mathews DB, Patten CA, Hammond CJ. Psilocybin history, action and reaction: A narrative clinical review. J Psychopharmacol 2023; 37:849-865. [PMID: 37650489 DOI: 10.1177/02698811231190858] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Hallucinogenic mushrooms have been used in religious and cultural ceremonies for centuries. Of late, psilocybin, the psychoactive compound in hallucinogenic mushrooms, has received increased public interest as a novel drug for treating mood and substance use disorders (SUDs). In addition, in recent years, some states in the United States have legalized psilocybin for medical and recreational use. Given this, clinicians need to understand the potential benefits and risks related to using psilocybin for therapeutic purposes so that they can accurately advise patients. This expert narrative review summarizes the scientific basis and clinical evidence on the safety and efficacy of psilocybin-assisted therapy for treating psychiatric disorders and SUDs. The results of this review are structured as a more extensive discussion about psilocybin's history, putative mechanisms of action, and recent legislative changes to its legal status. There is modest evidence of psilocybin-assisted therapy for treating depression and anxiety disorders. In addition, early data suggest that psilocybin-assisted therapy may effectively reduce harmful drinking in patients with alcohol use disorders. The evidence further suggests psilocybin, when administered under supervision (psilocybin-assisted therapy), the side effects experienced are mild and transient. The occurrence of severe adverse events following psilocybin administration is uncommon. Still, a recent clinical trial found that individuals in the psilocybin arm had increased suicidal ideations and non-suicidal self-injurious behaviors. Given this, further investigation into the safety and efficacy of psilocybin-assisted therapy is warranted to determine which patient subgroups are most likely to benefit and which are most likely to experience adverse outcomes related to its use.
Collapse
Affiliation(s)
- Pravesh Sharma
- Department of Psychiatry and Psychology, Mayo Clinic Health System, Eau Claire, WI, USA
- Behavioral Health Research Program, Department of Psychology and Psychiatry Research, Mayo Clinic, Rochester, MN, USA
| | - Quang Anh Nguyen
- Behavioral Health Research Program, Department of Psychology and Psychiatry Research, Mayo Clinic, Rochester, MN, USA
| | - Sadie J Matthews
- Department of Psychology, University of Wisconsin (Eau Claire), Eau Claire, WI, USA
| | | | - Douglas B Mathews
- Department of Psychology, University of Wisconsin (Eau Claire), Eau Claire, WI, USA
| | - Christi A Patten
- Behavioral Health Research Program, Department of Psychology and Psychiatry Research, Mayo Clinic, Rochester, MN, USA
| | - Christopher J Hammond
- Division of Child and Adolescent Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| |
Collapse
|
25
|
Szigeti B, Phillips LD, Nutt D. Bayesian analysis of real-world data as evidence for drug approval: Remembering Sir Michael Rawlins. Br J Clin Pharmacol 2023; 89:2646-2648. [PMID: 37455605 DOI: 10.1111/bcp.15841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023] Open
Affiliation(s)
- Balázs Szigeti
- Centre for Psychedelic Research, Division of Psychiatry, Imperial College London, London, UK
| | | | - David Nutt
- Centre for Psychedelic Research, Division of Psychiatry, Imperial College London, London, UK
| |
Collapse
|
26
|
Szigeti B, Nutt D, Carhart-Harris R, Erritzoe D. The difference between 'placebo group' and 'placebo control': a case study in psychedelic microdosing. Sci Rep 2023; 13:12107. [PMID: 37495637 PMCID: PMC10371989 DOI: 10.1038/s41598-023-34938-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 05/10/2023] [Indexed: 07/28/2023] Open
Abstract
In medical trials, 'blinding' ensures the equal distribution of expectancy effects between treatment arms in theory; however, blinding often fails in practice. We use computational modelling to show how weak blinding, combined with positive treatment expectancy, can lead to an uneven distribution of expectancy effects. We call this 'activated expectancy bias' (AEB) and show that AEB can inflate estimates of treatment effects and create false positive findings. To counteract AEB, we introduce the Correct Guess Rate Curve (CGRC), a statistical tool that can estimate the outcome of a perfectly blinded trial based on data from an imperfectly blinded trial. To demonstrate the impact of AEB and the utility of the CGRC on empirical data, we re-analyzed the 'self-blinding psychedelic microdose trial' dataset. Results suggest that observed placebo-microdose differences are susceptible to AEB and are at risk of being false positive findings, hence, we argue that microdosing can be understood as active placebo. These results highlight the important difference between 'trials with a placebo-control group', i.e., when a placebo control group is formally present, and 'placebo-controlled trials', where patients are genuinely blind. We also present a new blinding integrity assessment tool that is compatible with CGRC and recommend its adoption.
Collapse
Affiliation(s)
- Balázs Szigeti
- Centre for Psychedelic Research, Imperial College London, London, UK.
| | - David Nutt
- Centre for Psychedelic Research, Imperial College London, London, UK
| | - Robin Carhart-Harris
- Psychedelics Division, Neuroscape, Department of Neurology, University of California San Francisco, San Francisco, USA
| | - David Erritzoe
- Centre for Psychedelic Research, Imperial College London, London, UK
| |
Collapse
|
27
|
Bălăeț M, Trender W, Hellyer PJ, Hampshire A. Associations between the use of psychedelics and other recreational drugs with mental health and resilience during the COVID-19 pandemic. Front Psychiatry 2023; 14:1184681. [PMID: 37398594 PMCID: PMC10307955 DOI: 10.3389/fpsyt.2023.1184681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 05/22/2023] [Indexed: 07/04/2023] Open
Abstract
The large-scale disruption to peoples' daily lives during the COVID-19 pandemic provides a context for examining whether use of substances such as psychedelics in a naturalistic (outside of a controlled environment) setting, is associated with better mental wellbeing and resilience relative to those who use other drugs, or who do not use drugs at all. We interrogate data from the Great British Intelligence Test and identify that 7.8% out of N = 30,598 unique respondents used recreational drugs inclusive of psychedelics, cannabis, cocaine, and MDMA during the COVID-19 pandemic. Recruitment materials did not mention drug use would be surveyed, thereby enabling us to model the relationship with mood and resilience in people who had not specifically self-selected themselves for a 'drug' study. We report that people form clusters, characterized by different real-world patterns of drug use, and the majority of psychedelics users also use cannabis. However, a subset of cannabis users do not use psychedelics, enabling a subtractive comparison. Those who primarily used psychedelics and cannabis during the COVID-19 pandemic had worse mood self-assessment and resilience scores compared to those who never used drugs or primarily used cannabis. This pattern was also evident for other recreational drug use clusters, except for those who primarily used MDMA and cannabis, who had better mood but were of too low incidence to have confidence in this estimate. These findings cast light on the significant differences in mental wellbeing between users of different drugs and the non-user population during a global-crisis and call for future research to explore the pharmacological, contextual and cultural variables associated with these differences, their generalisability and causal links with greater precision.
Collapse
Affiliation(s)
- Maria Bălăeț
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - William Trender
- Department of Brain Sciences, Imperial College London, London, United Kingdom
- Engineering and Physical Sciences Research Council CDT Neurotechnology, Imperial College London, London, United Kingdom
| | - Peter J. Hellyer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Adam Hampshire
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| |
Collapse
|
28
|
Fissler P, Vandersmissen A, Filippi M, Mavioglu RN, Scholkmann F, Karabatsiakis A, Krähenmann R. Effects of serotonergic psychedelics on mitochondria: Transdiagnostic implications for mitochondria-related pathologies. J Psychopharmacol 2023:2698811231164707. [PMID: 37122193 DOI: 10.1177/02698811231164707] [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: 05/02/2023]
Abstract
The use of serotonergic psychedelics has gained increasing attention in research, clinical practice and society. Growing evidence suggests fast-acting, transdiagnostic health benefits of these 5-hydroxytryptamine 2A receptor agonists. Here, we provide a brief overview of their benefits for psychological, cardiovascular, metabolic, neurodegenerative, and immunological pathologies. We then review their effect on mitochondria including mitochondrial biogenesis, functioning and transport. Mitochondrial dysregulation is a transdiagnostic mechanism that contributes to the aforementioned pathologies. Hence, we postulate that psychedelic-induced effects on mitochondria partially underlie their transdiagnostic benefits. Based on this assumption, we propose new treatment indications for psychedelics and that the health benefits induced by psychedelics depend on patient-specific mitochondrial dysregulation.
Collapse
Affiliation(s)
- Patrick Fissler
- Psychiatric Services Thurgau, Spital Thurgau AG, Münsterlingen, Switzerland
- University Hospital for Psychiatry and Psychotherapy, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Anja Vandersmissen
- Psychiatric Services Thurgau, Spital Thurgau AG, Münsterlingen, Switzerland
- University Hospital for Psychiatry and Psychotherapy, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Marco Filippi
- Psychiatric Services Thurgau, Spital Thurgau AG, Münsterlingen, Switzerland
- University Hospital for Psychiatry and Psychotherapy, Paracelsus Medical University Salzburg, Salzburg, Austria
| | | | - Felix Scholkmann
- Biomedical Optics Research Laboratory, Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Alexander Karabatsiakis
- Department of Psychology, Clinical Psychology II, University of Innsbruck, Innsbruck, Austria
| | - Rainer Krähenmann
- Psychiatric Services Thurgau, Spital Thurgau AG, Münsterlingen, Switzerland
- University Hospital for Psychiatry and Psychotherapy, Paracelsus Medical University Salzburg, Salzburg, Austria
- Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zürich, Zürich, Switzerland
| |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
Nutt D, Spriggs M, Erritzoe D. Psychedelics therapeutics: What we know, what we think, and what we need to research. Neuropharmacology 2023; 223:109257. [PMID: 36179919 DOI: 10.1016/j.neuropharm.2022.109257] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/07/2022] [Accepted: 09/11/2022] [Indexed: 12/14/2022]
Abstract
Psychedelic therapy is perhaps the most exciting new development in psychiatry. Not only does it offer a radical new approach to treatment where mainstream approaches have proven ineffective, but the growing evidence for transdiagnostic efficacy is eliciting a re-think of current diagnostic and symptom-specific approaches to psychiatry. This excitement has led to a massive investment in this field with many tens of new pharmaceutical companies being set up to research the effects of known psychedelics and develop new patentable molecules. Whilst this enthusiasm is to be welcomed, it is important that new research is properly grounded in established facts and reflects current knowledge. In this commentary we lay out the knowledge framework that should be taken into account by all innovative researchers in this field.
Collapse
Affiliation(s)
- David Nutt
- Centres for Neuropsychopharmacology and Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - Meg Spriggs
- Centres for Neuropsychopharmacology and Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - David Erritzoe
- Centres for Neuropsychopharmacology and Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK.
| |
Collapse
|
31
|
Kinderlehrer DA. The Effectiveness of Microdosed Psilocybin in the Treatment of Neuropsychiatric Lyme Disease: A Case Study. Int Med Case Rep J 2023; 16:109-115. [PMID: 36896410 PMCID: PMC9990519 DOI: 10.2147/imcrj.s395342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 01/25/2023] [Indexed: 03/06/2023] Open
Abstract
Lyme disease can result in severe neuropsychiatric symptoms that may be resistant to treatment. The pathogenesis of neuropsychiatric Lyme disease is associated with autoimmune induced neuroinflammation. This case report describes an immunocompetent male with serologically positive neuropsychiatric Lyme disease who did not tolerate antimicrobial or psychotropic medications and whose symptoms remitted when he began psilocybin in microdosed (sub-hallucinogenic) amounts. A literature review of its therapeutic benefits reveals that psilocybin is both serotonergic and anti-inflammatory and therefore may offer significant therapeutic benefits to patients with mental illness secondary to autoimmune inflammation. The role of microdosed psilocybin in the treatment of neuropsychiatric Lyme disease and autoimmune encephalopathies warrants further study.
Collapse
|
32
|
Rosenblat JD, Husain MI, Lee Y, McIntyre RS, Mansur RB, Castle D, Offman H, Parikh SV, Frey BN, Schaffer A, Greenway KT, Garel N, Beaulieu S, Kennedy SH, Lam RW, Milev R, Ravindran AV, Tourjman V, Ameringen MV, Yatham LN, Taylor V. The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: Serotonergic Psychedelic Treatments for Major Depressive Disorder. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2023; 68:5-21. [PMID: 35975555 PMCID: PMC9720483 DOI: 10.1177/07067437221111371] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Serotonergic psychedelics are re-emerging as potential novel treatments for several psychiatric disorders including major depressive disorder. The Canadian Network for Mood and Anxiety Treatments (CANMAT) convened a task force to review the evidence and provide a consensus recommendation for the clinical use of psychedelic treatments for major depressive disorder. METHODS A systematic review was conducted to identify contemporary clinical trials of serotonergic psychedelics for the treatment of major depressive disorder and cancer-related depression. Studies published between January 1990 and July 2021 were identified using combinations of search terms, inspection of bibliographies and review of other psychedelic reviews and consensus statements. The levels of evidence for efficacy were graded according to the Canadian Network for Mood and Anxiety Treatments criteria. RESULTS Only psilocybin and ayahuasca have contemporary clinical trials evaluating antidepressant effects. Two pilot studies showed preliminary positive effects of single-dose ayahuasca for treatment-resistant depression (Level 3 evidence). Small randomized controlled trials of psilocybin combined with psychotherapy showed superiority to waitlist controls and comparable efficacy and safety to an active comparator (escitalopram with supportive psychotherapy) in major depressive disorder, with additional randomized controlled trials showing efficacy specifically in cancer-related depression (Level 3 evidence). There was only one open-label trial of psilocybin in treatment-resistant unipolar depression (Level 4 evidence). Small sample sizes and functional unblinding were major limitations in all studies. Adverse events associated with psychedelics, including psychological (e.g., psychotomimetic effects) and physical (e.g., nausea, emesis and headaches) effects, were generally transient. CONCLUSIONS There is currently only low-level evidence to support the efficacy and safety of psychedelics for major depressive disorder. In Canada, as of 2022, psilocybin remains an experimental option that is only available through clinical trials or the special access program. As such, Canadian Network for Mood and Anxiety Treatments considers psilocybin an experimental treatment and recommends its use primarily within clinical trials, or, less commonly, through the special access program in rare, special circumstances.
Collapse
Affiliation(s)
- Joshua D. Rosenblat
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - M. Ishrat Husain
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental
Health Research Institute Toronto, Ontario, Canada
| | - Yena Lee
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - Roger S. McIntyre
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - Rodrigo B. Mansur
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - David Castle
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental
Health Research Institute Toronto, Ontario, Canada
| | - Hilary Offman
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Sagar V. Parikh
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Depression Program, Michigan Medicine, University of Michigan, Ann
Arbor, USA
| | - Benicio N. Frey
- Mood Disorders Program, St. Joseph's Healthcare Hamilton, McMaster
University, Psychiatry & Behavioural Neurosciences, Hamilton, Ontario,
Canada
| | - Ayal Schaffer
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Department of Psychiatry, Sunnybrook Health Sciences Centre,
Toronto, Ontario, Canada
| | | | - Nicolas Garel
- McGill University, Psychiatry, Montreal, Quebec, Canada
| | | | - Sidney H. Kennedy
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - Raymond W. Lam
- Department of Psychiatry, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Roumen Milev
- Department of Psychiatry, Providence Care, Queen's University,
Kingston, ON, Canada
| | - Arun V. Ravindran
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental
Health Research Institute Toronto, Ontario, Canada
| | - Valerie Tourjman
- Institut universitaire en santé mentale de Montréal, Psychiatry,
Montreal, Quebec, Canada
| | - Michael Van Ameringen
- McMaster University Medical Centre, Anxiety Disorders Clinic,
Hamilton, Ontario, Canada
| | - Lakshmi N. Yatham
- Department of Psychiatry, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Valerie Taylor
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| |
Collapse
|
33
|
van der Meer PB, Fuentes JJ, Kaptein AA, Schoones JW, de Waal MM, Goudriaan AE, Kramers K, Schellekens A, Somers M, Bossong MG, Batalla A. Therapeutic effect of psilocybin in addiction: A systematic review. Front Psychiatry 2023; 14:1134454. [PMID: 36846225 PMCID: PMC9947277 DOI: 10.3389/fpsyt.2023.1134454] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
BACKGROUND Psychedelic-assisted therapy [e.g., with lysergic acid diethylamide (LSD)] has shown promising results as treatment for substance use disorders (SUDs). Previous systematic reviews assessing the efficacy of psilocybin in SUDs only included clinical trials conducted in the last 25 years, but they may have missed clinical trials assessing the efficacy of psilocybin that were conducted before the 1980s, given much research has been done with psychedelics in the mid-20th century. In this systematic review, we specifically assessed the efficacy of psilocybin in patients with a SUD or non-substance-related disorder with no publication date restrictions in our search strategy. METHODS A systematic literature search was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines from the earliest published manuscript up to September 2, 2022, in seven electronic databases, including clinical trials in patients with a SUD or non-substance-related disorder evaluating the efficacy of psilocybin. RESULTS A total of four studies (six articles, of which two articles were long-term follow-up results from the same trial) were included in this systematic review. Psilocybin-assisted therapy was administered to n = 151 patients in a dose ranging from 6 to 40 mg. Three studies focused on alcohol use disorder, and one study on tobacco use disorder. In a pilot study (n = 10), the percentage of heavy drinking days decreased significantly between baseline and weeks 5-12 (mean difference of 26.0, 95% CI = 8.7-43.2, p = 0.008). In another single-arm study (n = 31), 32% (10/31) became completely abstinent from alcohol (mean duration of follow-up 6 years). In a double-blind, placebo-controlled randomized controlled trial (RCT, n = 95), the percentage of heavy drinking days during the 32-week double-blind period was significantly lower for psilocybin compared to placebo (mean difference of 13.9, 95% CI = 3.0-24.7, p = 0.01). In a pilot study (n = 15), the 7-day point prevalence of smoking abstinence at 26 weeks was 80% (12/15), and at 52 weeks 67% (10/15). CONCLUSION Only one RCT and three small clinical trials were identified assessing the efficacy of psilocybin combined with some form of psychotherapy in patients with alcohol and tobacco use disorder. All four clinical trials indicated a beneficial effect of psilocybin-assisted therapy on SUD symptoms. Larger RCTs in patients with SUDs need to evaluate whether psilocybin-assisted therapy is effective in patients with SUD.
Collapse
Affiliation(s)
- Pim B van der Meer
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands.,Department of Psychiatry, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Juan J Fuentes
- Addiction Program, Institute of Neuropsychiatry and Addictions (INAD), Hospital del Mar, Barcelona, Spain.,Addiction Research Group, IMIM Hospital del Mar Medical Research Institute, Barcelona, Spain.,Department of Psychiatry and Legal Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallés, Spain
| | - Ad A Kaptein
- Department of Medical Psychology, Leiden University Medical Center, Leiden, Netherlands
| | - Jan W Schoones
- Directorate of Research Policy, Leiden University Medical Center, Leiden, Netherlands
| | - Marleen M de Waal
- Department of Research and Jellinek, Arkin Mental Health Care, Amsterdam, Netherlands.,Department of Psychiatry, Amsterdam University Medical Center, Amsterdam, Netherlands.,Amsterdam Institute for Addiction Research, Amsterdam University Medical Center, Amsterdam, Netherlands
| | - Anneke E Goudriaan
- Department of Research and Jellinek, Arkin Mental Health Care, Amsterdam, Netherlands.,Department of Psychiatry, Amsterdam University Medical Center, Amsterdam, Netherlands.,Amsterdam Institute for Addiction Research, Amsterdam University Medical Center, Amsterdam, Netherlands
| | - Kees Kramers
- Department of Pharmacology-Toxicology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Arnt Schellekens
- Nijmegen Institute for Science Practitioners in Addiction (NISPA), Nijmegen, Netherlands.,Department of Psychiatry, Radboud University Medical Center, Nijmegen, Netherlands
| | - Metten Somers
- Department of Psychiatry, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Matthijs G Bossong
- Department of Psychiatry, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Albert Batalla
- Department of Psychiatry, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| |
Collapse
|
34
|
Could psychedelic drugs have a role in the treatment of schizophrenia? Rationale and strategy for safe implementation. Mol Psychiatry 2023; 28:44-58. [PMID: 36280752 DOI: 10.1038/s41380-022-01832-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 10/02/2022] [Accepted: 10/07/2022] [Indexed: 01/07/2023]
Abstract
Schizophrenia is a widespread psychiatric disorder that affects 0.5-1.0% of the world's population and induces significant, long-term disability that exacts high personal and societal cost. Negative symptoms, which respond poorly to available antipsychotic drugs, are the primary cause of this disability. Association of negative symptoms with cortical atrophy and cell loss is widely reported. Psychedelic drugs are undergoing a significant renaissance in psychiatric disorders with efficacy reported in several conditions including depression, in individuals facing terminal cancer, posttraumatic stress disorder, and addiction. There is considerable evidence from preclinical studies and some support from human studies that psychedelics enhance neuroplasticity. In this Perspective, we consider the possibility that psychedelic drugs could have a role in treating cortical atrophy and cell loss in schizophrenia, and ameliorating the negative symptoms associated with these pathological manifestations. The foremost concern in treating schizophrenia patients with psychedelic drugs is induction or exacerbation of psychosis. We consider several strategies that could be implemented to mitigate the danger of psychotogenic effects and allow treatment of schizophrenia patients with psychedelics to be implemented. These include use of non-hallucinogenic derivatives, which are currently the focus of intense study, implementation of sub-psychedelic or microdosing, harnessing of entourage effects in extracts of psychedelic mushrooms, and blocking 5-HT2A receptor-mediated hallucinogenic effects. Preclinical studies that employ appropriate animal models are a prerequisite and clinical studies will need to be carefully designed on the basis of preclinical and translational data. Careful research in this area could significantly impact the treatment of one of the most severe and socially debilitating psychiatric disorders and open an exciting new frontier in psychopharmacology.
Collapse
|
35
|
Moujaes F, Preller KH, Ji JL, Murray JD, Berkovitch L, Vollenweider FX, Anticevic A. Towards mapping neuro-behavioral heterogeneity of psychedelic neurobiology in humans. Biol Psychiatry 2022:S0006-3223(22)01805-4. [PMID: 36715317 DOI: 10.1016/j.biopsych.2022.10.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/10/2022] [Accepted: 10/31/2022] [Indexed: 12/12/2022]
Abstract
Precision psychiatry aims to identify markers of inter-individual variability that allow predicting the right treatment for each patient. However, bridging the gap between molecular-level manipulations and neural systems-level functional alterations remains an unsolved problem in psychiatry. After decades of low success rates in pharmaceutical R&D for psychiatric drugs, multiple studies now point to the potential of psychedelics as a promising fast-acting and long-lasting treatment for some psychiatric symptoms. Yet, given the highly psychoactive nature of these substances, a precision medicine approach is essential to map the neural signals related to clinical efficacy in order to identify patients who can maximally benefit from this treatment. Recent studies have shown that bridging the gap between pharmacology, systems-level neural response in humans and individual experience is possible for psychedelic substances, therefore paving the way for a precision neuropsychiatric therapeutic development. Specifically, it has been shown that the integration of brain-wide PET or transcriptomic data, i.e. receptor distribution for the serotonin 2A receptor, with computational neuroimaging methods can simulate the effect of psychedelics on the human brain. These novel 'computational psychiatry' approaches allow for modeling inter-individual differences in neural as well as subjective effects of psychedelic substances. Collectively, this review provides a deep dive into psychedelic pharmaco-neuroimaging studies with a core focus on how recent computational psychiatry advances in biophysically based circuit modeling can be leveraged to predict individual responses. Finally, we emphasize the importance of human pharmacological neuroimaging for the continued precision therapeutic development of psychedelics.
Collapse
Affiliation(s)
- Flora Moujaes
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry Zurich, Lenggstr. 31, 8032 Zurich, Switzerland; Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States
| | - Katrin H Preller
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry Zurich, Lenggstr. 31, 8032 Zurich, Switzerland; Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States
| | - Jie Lisa Ji
- Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States
| | - John D Murray
- Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States; Department of Physics, Yale University, New Haven, CT, 06511, United States; Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06511, United States
| | - Lucie Berkovitch
- Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States; Université de Paris, 15 Rue de l'École de Médecine, F-75006 Paris, France; Department of Psychiatry, Service Hospitalo-Universitaire, GHU Paris Psychiatrie & Neurosciences, 1 rue Cabanis, F-75014, Paris, France
| | - Franz X Vollenweider
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry Zurich, Lenggstr. 31, 8032 Zurich, Switzerland
| | - Alan Anticevic
- Department of Psychiatry, Yale University School of Medicine, 40 Temple Street, New Haven, CT, 06511, United States; Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06511, United States.
| |
Collapse
|
36
|
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.
Collapse
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.
| |
Collapse
|
37
|
Bonnelle V, Smith WJ, Mason NL, Cavarra M, Kryskow P, Kuypers KPC, Ramaekers JG, Feilding A. Analgesic potential of macrodoses and microdoses of classical psychedelics in chronic pain sufferers: a population survey. Br J Pain 2022; 16:619-631. [PMID: 36452124 PMCID: PMC9703241 DOI: 10.1177/20494637221114962] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023] Open
Abstract
Although several studies and reports have shown the potential analgesic use of serotonergic psychedelics in cancer pain, phantom limb pain and cluster headache, evidence supporting their use for chronic pain is still limited. The past years have seen a considerable renewal of interest toward the therapeutic use of these compounds for mood disorders, resulting in a marked increase in the number of people turning to psychedelics in an attempt to self-medicate a health condition or improve their wellbeing. In western countries particularly, this population of users overlaps substantially with chronic pain sufferers, representing a unique opportunity to evaluate the effects these compounds have on pain and wellbeing. Here, we report results from an online survey conducted between August 2020 and July 2021 in a population of 250 chronic pain sufferers who had experience with psychedelics, either in microdoses (small sub-hallucinogenic doses), macrodoses (hallucinogenic doses), or both. Macrodoses, while less often used for analgesic purposes than microdoses, were reported to induce a higher level of pain relief than both microdoses and conventional pain medications (including opioids and cannabis). Although the effects were weaker and potentially more prone to expectation bias than with macrodoses, our results also suggested some benefits of psychedelics in microdoses for pain management. The reported analgesic effect appeared unrelated to mood improvements associated with psychedelic use, or the advocacy of psychedelic use. Taken together, our findings indicate interesting potential analgesic applications for psychedelics that warrant further clinical research.
Collapse
Affiliation(s)
| | | | - Natasha L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Mauro Cavarra
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Pamela Kryskow
- Department of Family Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Kim PC Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | | |
Collapse
|
38
|
Isham A, Elf P, Jackson T. Self-transcendent experiences as promoters of ecological wellbeing? Exploration of the evidence and hypotheses to be tested. Front Psychol 2022; 13:1051478. [PMID: 36452396 PMCID: PMC9701724 DOI: 10.3389/fpsyg.2022.1051478] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 10/26/2022] [Indexed: 08/15/2023] Open
Abstract
In recent years, much has been written on the role of different mental states and their potential to influence our way of thinking and, perhaps more importantly, the way we act. With the recent acceleration of environmental and mental health issues, alongside the limited effectiveness of existing interventions, an exploration of new approaches to deliver transformative change is required. We therefore explore the emerging potential of a type of mental state known as self-transcendent experiences (STEs) as a driver of ecological wellbeing. We focus on four types of STEs: those facilitated by experiences of flow, awe, and mindfulness, as well as by psychedelic-induced experiences. Some of these experiences can occur naturally, through sometimes unexpected encounters with nature or during immersion in every-day activities that one intrinsically enjoys, as well as through more intentional practices such as meditation or the administration of psychedelics in controlled, legal settings. We explore the evidence base linking each of the four types of STE to ecological wellbeing before proposing potential hypotheses to be tested to understand why STEs can have such beneficial effects. We end by looking at the factors that might need to be considered if STEs are going to be practically implemented as a means of achieving ecological wellbeing.
Collapse
Affiliation(s)
- Amy Isham
- Centre for the Understanding of Sustainable Prosperity (CUSP), Centre for Environment and Sustainability, University of Surrey, Guildford, United Kingdom
- School of Psychology, Swansea University, Swansea, United Kingdom
| | - Patrick Elf
- Middlesex University Business School, Centre for Enterprise and Economic Development Research (CEEDR), Middlesex University, London, United Kingdom
| | - Tim Jackson
- Centre for the Understanding of Sustainable Prosperity (CUSP), Centre for Environment and Sustainability, University of Surrey, Guildford, United Kingdom
| |
Collapse
|
39
|
Abstract
With the extensive public, commercial and scientific interest from what has been widely termed the psychedelic renaissance, it is important that the scientific practices and results obtained from its implementation into medicine are put under a critical microscope. While there are numerous works on the potential benefits and applications of psychedelics as medicines, relatively little has been written about the challenges this field will face when incorporated into modern medical practice. Indeed, as a new or at least revived area of investigation, psychedelic medicine has a particular set of challenges which need to be addressed. In this viewpoint, we identify a number of these challenges. First, challenges related to the design of individual research studies are discussed, particularly focusing on current practices surrounding blinding, expectancy, the use of therapy and sources of bias. Second, the broader context of the research environment is considered, including how medical science typically establishes evidence, funding bodies and the impact of psychedelics being scheduled at odds with their risk profile. Finally, we describe challenges relating to the implementation of psychedelic therapies into modern medicine, considering the social and economic context. Alongside, we provide suggestions for what could be included into current research protocols to mitigate these challenges.
Collapse
Affiliation(s)
| | - Anna Forsyth
- School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Rachael L Sumner
- School of Pharmacy, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
40
|
Psilocybin Efficacy and Mechanisms of Action in Major Depressive Disorder: a Review. Curr Psychiatry Rep 2022; 24:573-581. [PMID: 35953638 DOI: 10.1007/s11920-022-01361-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/28/2022] [Indexed: 01/29/2023]
Abstract
PURPOSE OF THE REVIEW We aim to provide an overview of the current state of knowledge about the efficacy of psilocybin in the treatment of depression, as well as its mechanisms of action. RECENT FINDINGS Psilocybin has a large, rapid, and persistent clinical effect in the treatment of resistant or end-of-life depression. Tolerance is good, with mild side effects limited to a few hours after dosing. The studies conducted to date have had small sample sizes. One clinical trial has been conducted against a reference treatment (escitalopram) without showing a significant superiority of psilocybin in the main outcome. The neurobiological mechanisms, mostly unknown, differ from those of SSRI antidepressants. Psilocybin represents a promising alternative in the treatment of depression. Further research with larger sample sizes, particularly against reference treatments, is needed to better understand the neurobiological factors of its effects and to investigate its potential for use in everyday practice.
Collapse
|
41
|
Kaypak AC, Raz A. Macrodosing to microdosing with psychedelics: Clinical, social, and cultural perspectives. Transcult Psychiatry 2022; 59:665-674. [PMID: 36031848 DOI: 10.1177/13634615221119386] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To date, the clinical and scientific literature has best documented the effects of classical psychedelics, such as lysergic acid diethylamide (LSD), psilocybin, and dimethyltryptamine (DMT), in typical quantities most often associated with macrodosing. More recently, however, microdosing with psychedelics has emerged as a social trend and nascent therapeutic intervention. This variation in psychedelic practice refers to repeat, intermittent ingestion of less-than-macrodose amounts that do not cause the effects associated with full-blown "trips". Microdosing paves the road to incorporating psychedelic drugs into a daily routine while maintaining, or even improving, cognitive and mental function. Unlike macrodosing with psychedelics, the influence of microdosing remains mostly unexplored. And yet, despite the paucity of formal studies, many informal accounts propose that microdosing plays an important role as both a therapeutic intervention (e.g., in mental disorders) and enhancement tool (e.g., recreationally-to boost creativity, improve cognition, and drive personal growth). In response to this relatively new practice, we provide an integrative synthesis of the clinical, social, and cultural dimensions of microdosing. We describe some of the overarching context that explains why this practice is increasingly in vogue, unpack potential benefits and risks, and comment on sociocultural implications. In addition, this article considers the effects that macro- and microdoses have on behavior and psychopathology in light of their dosage characteristics and contexts of use.
Collapse
Affiliation(s)
- Ayse Ceren Kaypak
- Lady Davis Institute for Medical Research, 293290Institute for Community and Family Psychiatry, Jewish General Hospital, Montreal, QC, Canada.,Department of Psychiatry, 64050Marmara University School of Medicine, Istanbul, Turkey
| | - Amir Raz
- Lady Davis Institute for Medical Research, 293290Institute for Community and Family Psychiatry, Jewish General Hospital, Montreal, QC, Canada.,Departments of Psychiatry, Psychology, and Neurology & Neurosurgery, 5620McGill University, Montreal, QC, Canada.,Montreal Neurological Institute, 5620McGill University, Montreal, QC, Canada.,Institute for Interdisciplinary Brain and Behavioral Sciences, 6226Chapman University, Irvine, CA, USA
| |
Collapse
|
42
|
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.
Collapse
Affiliation(s)
| | - Amir Raz
- 6226Chapman University, USA.,5620McGill University, Canada.,Jewish General Hospital, Canada
| |
Collapse
|
43
|
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.
Collapse
|
44
|
Plackett B. Psychedelic microdosing hits a rough patch in clinical trials. Nature 2022; 609:S96-S97. [PMID: 36171364 DOI: 10.1038/d41586-022-02876-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
45
|
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.
Collapse
|
46
|
Nygart VA, Pommerencke LM, Haijen E, Kettner H, Kaelen M, Mortensen EL, Nutt DJ, Carhart-Harris RL, Erritzoe D. Antidepressant effects of a psychedelic experience in a large prospective naturalistic sample. J Psychopharmacol 2022; 36:932-942. [PMID: 35924888 PMCID: PMC9353970 DOI: 10.1177/02698811221101061] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Over the last two decades, a number of studies have highlighted the potential of psychedelic therapy. However, questions remain to what extend these results translate to naturalistic samples, and how contextual factors and the acute psychedelic experience relate to improvements in affective symptoms following psychedelic experiences outside labs/clinics. The present study sought to address this knowledge gap. AIM Here, we aimed to investigate changes in anxiety and depression scores before versus after psychedelic experiences in naturalistic contexts, and how various pharmacological, extrapharmacological and experience factors related to outcomes. METHOD Individuals who planned to undergo a psychedelic experience were enrolled in this online survey study. Depressive symptoms were assessed at baseline and 2 and 4 weeks post-psychedelic experience, with self-rated Quick Inventory of Depressive Symptomatology (QIDS-SR-16) as the primary outcome. To facilitate clinical translation, only participants with depressive symptoms at baseline were included. Sample sizes for the four time points were N = 302, N = 182, N = 155 and N = 109, respectively. RESULTS Relative to baseline, reductions in depressive symptoms were observed at 2 and 4 weeks. A medicinal motive, previous psychedelic use, drug dose and the type of acute psychedelic experience (i.e. specifically, having an emotional breakthrough) were all significantly associated with changes in self-rated QIDS-SR-16. CONCLUSION These results lend support to therapeutic potential of psychedelics and highlight the influence of pharmacological and non-pharmacological factors in determining response. Mindful of a potential sample and attrition bias, further controlled and observational longitudinal studies are needed to test the replicability of these findings.
Collapse
Affiliation(s)
- Victoria Amalie Nygart
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| | - Lis Marie Pommerencke
- National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
| | - Eline Haijen
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| | - Hannes Kettner
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| | - Mendel Kaelen
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| | - Erik Lykke Mortensen
- Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - David John Nutt
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| | - Robin Lester Carhart-Harris
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| | - David Erritzoe
- Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Centers for Neuropsychopharmacology and Psychedelic Research, Imperial College London, London, UK
| |
Collapse
|
47
|
Fernandes-Nascimento MH, Viana-Ferreira K, Chaves BDR, Negrão AB, Wang YP. Ibogaine microdosing in a patient with bipolar depression: a case report. REVISTA BRASILEIRA DE PSIQUIATRIA (SAO PAULO, BRAZIL : 1999) 2022; 44. [PMID: 35896190 PMCID: PMC9375667 DOI: 10.47626/1516-4446-2021-2359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022]
Affiliation(s)
- Maria Helha Fernandes-Nascimento
- Instituto de Psiquiatria (LIM-23), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Karine Viana-Ferreira
- Programa de Pós-Graduação em Fisiopatologia Experimental, Departamento de Patologia, FMUSP, São Paulo, SP, Brazil
| | | | - André Brooking Negrão
- Grupo Interdisciplinar de Estudos sobre Álcool e Drogas, Departamento e Instituto de Psiquiatria, Hospital das Clínicas, FMUSP, São Paulo, SP, Brazil
| | - Yuan-Pang Wang
- Instituto de Psiquiatria (LIM-23), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| |
Collapse
|
48
|
van Elk M, Yaden DB. Pharmacological, neural, and psychological mechanisms underlying psychedelics: A critical review. Neurosci Biobehav Rev 2022; 140:104793. [PMID: 35878791 DOI: 10.1016/j.neubiorev.2022.104793] [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: 01/15/2022] [Revised: 07/08/2022] [Accepted: 07/20/2022] [Indexed: 10/17/2022]
Abstract
This paper provides a critical review of several possible mechanisms at different levels of analysis underlying the effects and therapeutic potential of psychedelics. At the (1) biochemical level, psychedelics primarily affect the 5-HT2A receptor, increase neuroplasticity, offer a critical period for social reward learning, and have anti-inflammatory properties. At the (2) neural level, psychedelics have been associated with reduced efficacy of thalamo-cortical filtering, the loosening of top-down predictive signaling and an increased sensitivity to bottom-up prediction errors, and activation of the claustro-cortical-circuit. At the (3) psychological level, psychedelics have been shown to induce altered and affective states, they affect cognition, induce belief change, exert social effects, and can result in lasting changes in behavior. We outline the potential for a unifying account of the mechanisms underlying psychedelics and contrast this with a model of pluralistic causation. Ultimately, a better understanding of the specific mechanisms underlying the effects of psychedelics could allow for a more targeted therapeutic approach. We highlight current challenges for psychedelic research and provide a research agenda to foster insight in the causal-mechanistic pathways underlying the efficacy of psychedelic research and therapy.
Collapse
Affiliation(s)
- Michiel van Elk
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333 AK Leiden, the Netherlands.
| | - David Bryce Yaden
- The Center for Psychedelic and Consciousness Research, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA
| |
Collapse
|
49
|
Dodd S, Norman TR, Eyre HA, Stahl SM, Phillips A, Carvalho AF, Berk M. Psilocybin in neuropsychiatry: a review of its pharmacology, safety, and efficacy. CNS Spectr 2022; 28:1-11. [PMID: 35811423 DOI: 10.1017/s1092852922000888] [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] [Indexed: 11/05/2022]
Abstract
Psilocybin is a tryptamine alkaloid found in some mushrooms, especially those of the genus Psilocybe. Psilocybin has four metabolites including the pharmacologically active primary metabolite psilocin, which readily enters the systemic circulation. The psychoactive effects of psilocin are believed to arise due to the partial agonist effects at the 5HT2A receptor. Psilocin also binds to various other receptor subtypes although the actions of psilocin at other receptors are not fully explored. Psilocybin administered at doses sufficient to cause hallucinogenic experiences has been trialed for addictive disorders, anxiety and depression. This review investigates studies of psilocybin and psilocin and assesses the potential for use of psilocybin and a treatment agent in neuropsychiatry. The potential for harm is also assessed, which may limit the use of psilocybin as a pharmacotherapy. Careful evaluation of the number needed to harm vs the number needed to treat will ultimately justify the potential clinical use of psilocybin. This field needs a responsible pathway forward.
Collapse
Affiliation(s)
- Seetal Dodd
- IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
- School of Medicine, Deakin University, Geelong, VIC, Australia
- University Hospital Geelong, Barwon Health, Geelong, VIC, Australia
- Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
- Centre for Youth Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Trevor R Norman
- Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
| | - Harris A Eyre
- IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Neuroscience-Inspired Policy Initiative, Organisation for Economic Co-Operation and Development (OECD), Meadows Mental Health Policy Institute and the PRODEO Institute, Paris, France
- Global Brain Health Institute, University of California, San Francisco (UCSF), San Francisco, CA, USA
- Global Brain Health Institute, Trinity College Dublin, Dublin, Ireland
- Latin American Brain Health (BrainLat), Universidad Adolfo Ibáñez, Santiago, Chile
- Brain Health Nexus, Cohen Veterans Network, Boston, MA, USA
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Stephen M Stahl
- Department of Psychiatry, University of California San Diego, San Diego, CA, USA
| | - Arnie Phillips
- IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
- School of Medicine, Deakin University, Geelong, VIC, Australia
| | - André F Carvalho
- IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
- School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Michael Berk
- IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
- School of Medicine, Deakin University, Geelong, VIC, Australia
- University Hospital Geelong, Barwon Health, Geelong, VIC, Australia
- Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
- Centre for Youth Mental Health, The University of Melbourne, Parkville, VIC, Australia
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
50
|
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]
|