Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction

Psilocybin for alcohol use disorder: Rationale and design considerations for a randomized controlled trial

Several lines of evidence suggest that classic psychedelics (5-HT_2A receptor agonists or partial agonists) such as psilocybin might facilitate behavior change in individuals with substance use disorders. We conducted a multi-site, double-blind, randomized controlled trial (RCT) to assess the effects of psilocybin-assisted psychotherapy in alcohol-dependent volunteers. In addition to a structured 12-week psychotherapy platform, participants (n = 96) were randomly assigned (1:1) to receive either oral psilocybin or an active placebo (oral diphenhydramine) in each of two dosing sessions (at weeks 4 and 8). Initial doses were 25 mg/70 kg psilocybin or 50 mg diphenhydramine, which could be increased in the second session depending on initial response. The psychotherapy platform combined evidence-based, manualized therapy for alcohol dependence with a supportive context for the dosing sessions. All participants were followed in the RCT through week 36. At the end of the RCT, participants who still met safety criteria were offered an open-label psilocybin session. Data collected at screening, baseline and throughout the study included: demographics, measures of alcohol use, subjective response to psilocybin and diphenhydramine, and safety measures. The primary outcome was the proportion of heavy drinking days during the 32 weeks after the first dosing session (i.e., between week 4 and week 36). Secondary outcomes included safety, additional measures of drinking (e.g., abstinence, drinking days, etc.), craving, self-efficacy, and acute effects. We will also explore moderators and mediators of the primary outcome. The primary outcomes will be published elsewhere. In this paper, we describe the protocol and rationale for our design decisions.

Effect of lysergic acid diethylamide (LSD) on reinforcement learning in humans

BACKGROUND

The non-selective serotonin 2A (5-HT2A) receptor agonist lysergic acid diethylamide (LSD) holds promise as a treatment for some psychiatric disorders. Psychedelic drugs such as LSD have been suggested to have therapeutic actions through their effects on learning. The behavioural effects of LSD in humans, however, remain incompletely understood. Here we examined how LSD affects probabilistic reversal learning (PRL) in healthy humans.

METHODS

Healthy volunteers received intravenous LSD (75 μg in 10 mL saline) or placebo (10 mL saline) in a within-subjects design and completed a PRL task. Participants had to learn through trial and error which of three stimuli was rewarded most of the time, and these contingencies switched in a reversal phase. Computational models of reinforcement learning (RL) were fitted to the behavioural data to assess how LSD affected the updating ('learning rates') and deployment of value representations ('reinforcement sensitivity') during choice, as well as 'stimulus stickiness' (choice repetition irrespective of reinforcement history).

RESULTS

Raw data measures assessing sensitivity to immediate feedback ('win-stay' and 'lose-shift' probabilities) were unaffected, whereas LSD increased the impact of the strength of initial learning on perseveration. Computational modelling revealed that the most pronounced effect of LSD was the enhancement of the reward learning rate. The punishment learning rate was also elevated. Stimulus stickiness was decreased by LSD, reflecting heightened exploration. Reinforcement sensitivity differed by phase.

CONCLUSIONS

Increased RL rates suggest LSD induced a state of heightened plasticity. These results indicate a potential mechanism through which revision of maladaptive associations could occur in the clinical application of LSD.

Psychedelic/entactogen‐assisted therapy for treatment of anxiety, depression and existential distress in adult palliative care

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the benefits and harms of psychedelic/entactogen‐assisted therapy compared to placebo or active comparators (e.g. antidepressants) for treatment of anxiety, depression, and existential distress in adult palliative care.

Music programming for psilocybin-assisted therapy: Guided Imagery and Music-informed perspectives

The psychedelic drug psilocybin has been successfully explored as a novel treatment for a range of psychiatric disorders. Administration of psilocybin requires careful attention to psychological support and the setting in which the drug is administered. The use of music to support the acute psychoactive effects of psilocybin is recommended in current guidelines, but descriptions of how to compile music programs for the 4-6 h long sessions are still scarce. This article describes the procedural steps and considerations behind the curation of a new music program, the Copenhagen Music Program, tailored to the intensity profile of a medium/high dose psilocybin. The method of Guided Imagery and Music is presented as a music therapeutic framework for choosing and sequencing music in music programming and the Taxonomi of Therapeutic Music is presented as a rating tool to evaluate the music-psychological intensity of music pieces. Practical examples of how to organize the process of music programming are provided along with a full description of the Copenhagen Music Program and its structure. The aim of the article is to inspire others in their endeavours to create music programs for psychedelic interventions, while proposing that an informed music choice may support the therapeutic dynamics during acute effects of psilocybin.

Psilocybin as a Treatment for Psychiatric Illness: A Meta-Analysis

Psilocybin is an emerging potential therapy for the treatment of psychiatric illnesses. Microdosing has been shown to result in an overall improvement in patients with anxiety, depression, obsessive-compulsive disorder, post-traumatic stress disorder, and substance abuse. This meta-analysis explores and compiles prior research to make further inferences regarding psilocybin and its use for the treatment of psychiatric illness along with its safety and efficacy. Database searches were conducted to identify peer-reviewed randomized controlled trials and clinical trials mentioning psilocybin use and psychiatric illness. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram was created and analysis was run on the nine articles that met all established inclusion criteria. An event is defined as a participant who showed improvement, in a quantitative method, from baseline after the use of psilocybin. Another analysis was done using depression severity (Quick Inventory of Depressive Symptomatology 16-Item Self Report, QIDS-SR16) at baseline and after the use of psilocybin. Analyses of the original data and the nine articles showed a great deal of heterogeneity with an I² value of 73.68%, suggesting that the studies in this meta-analysis cannot be considered to be studies of the same population. The Q value of 30.4 was higher than 15.507, which is the critical value for eight degrees of freedom found in a chi-square distribution. This Q value showed a high degree of variation and lacked significance. The second meta-run on QIDS-SR16 scores from three studies showed a Q value of 1.16 which was lower than 5.991, the critical value for two degrees of freedom found in a chi-square distribution. The I² statistic for this second meta-analysis was -73% which can be equated to zero. This indicated that the data were homogeneous or that there was no observed heterogeneity. Due to low heterogeneity, the fixed-effects model was used. Based on this meta-analysis, psilocybin seems to show symptom improvement in some psychiatric illnesses. The effectiveness of psilocybin microdosing and the use of psilocybin, in general, need to be studied further to determine the efficacy and safety of potential applications in psychiatry.

Psilocybin-assisted therapy for reducing alcohol intake in patients with alcohol use disorder: protocol for a randomised, double-blinded, placebo-controlled 12-week clinical trial (The QUANTUM Trip Trial)

INTRODUCTION

Alcohol use disorder is a difficult-to-treat psychiatric disorder and a major burden on public health. Existing treatment efficacy is moderate, and relapse rates are high. Preliminary findings suggest that psilocybin, a psychedelic compound, can safely and reliably occasion highly meaningful experiences that may spur a positive change in drinking behaviour when administered in a therapeutic context. However, the efficacy of a single psilocybin administration and its potential neurobiological underpinnings still remain unknown.

METHODS AND ANALYSIS

To establish efficacy, we will investigate the effects of psilocybin-assisted therapy versus placebo in a randomised, double-blinded, placebo-controlled 12-week clinical trial. Ninety treatment-seeking patients, aged 20-70 years, diagnosed with alcohol use disorder will be recruited from the community via advertisement and referrals from general practitioners or specialised treatment units. The psilocybin or placebo will be administered in accordance with a protocol for psychological support before, during and after the dosing. Outcome assessments will be carried out 1, 4, 8 and 12 weeks postdosing. The primary outcome is reduction in the percentage of heavy drinking days from baseline to follow-up at 12 weeks. Key secondary outcomes are as follows: (1) total alcohol consumption, (2) phosphatidyl-ethanol, an objective biomarker for alcohol, (3) plasma psilocin, the active metabolite, to establish a possible therapeutic range, (4) the acute subjective drug experience as a possible predictor of treatment outcome and (5) neuronal response to alcohol cues and cognitive flexibility within corticostriatal pathways by use of functional MR brain imaging 1-week postdosing.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Committee on Health Research Ethics of the Capital Region of Denmark (H-20043832). All patients will be provided oral and written information about the trial before screening. The study results will be disseminated by peer-review publications and conference presentations.

TRIAL REGISTRATION NUMBER

EudraCT 2020-000829-55 and NCT05416229.

Race and ethnicity moderate the associations between lifetime psychedelic use (MDMA and psilocybin) and psychological distress and suicidality

Psychedelic compounds have been linked to salutary mental health outcomes in both naturalistic and clinical settings; however, current research on psychedelics suffers from a lack of inclusion and focus on racial and ethnic minorities. Thus, the goal of our study was to assess whether race and ethnicity moderate the associations that naturalistic lifetime MDMA (3,4-Methylenedioxymethamphetamine) use and psilocybin use share with past month psychological distress and past year suicidality (ideation and planning). Using data from the National Survey on Drug Use and Health (NSDUH) (2008-2019) (N = 484,732), we conducted survey-weighted multivariable logistic regression to conduct interaction tests and to assess the associations that MDMA use and psilocybin use share with the aforementioned outcomes for each racial and ethnic group. Race and ethnicity significantly moderated the associations between MDMA and psilocybin use and psychological distress and suicidality. For White participants, MDMA and psilocybin use conferred lowered odds of all distress and suicidality outcomes. For racial and ethnic minority participants, the associations between psychedelic use and suicidality were far fewer. These findings invite further research into the impact of race, ethnicity, and other identity factors (e.g., socioeconomic status, sexual/gender minority status) on the effects of psychedelic substances.

Lasting increases in trait mindfulness after psilocybin correlate positively with the mystical-type experience in healthy individuals

Background

Psilocybin-induced mystical-type experiences are associated with lasting positive psychological outcomes. Recent studies indicate that trait mindfulness is increased 3 months after psilocybin intake, preceded by decreases in neocortical serotonin 2A receptor (5-HT2AR) binding. However, the association between psilocybin-induced mystical-type experiences and subsequent changes in trait mindfulness remains unexplored, as does the association between pre-drug trait mindfulness and 5-HT2AR binding in the healthy brain.

Aim

We evaluated whether psilocybin induced lasting increases in trait mindfulness in healthy volunteers, and whether the mystical-type experience was associated with this increase. We further examined the association between pre-drug trait mindfulness and 5-HT2AR binding in neocortex and selected frontolimbic regions.

Materials and methods

Forty-six medium-high dose psilocybin sessions were conducted in 39 healthy individuals. The mystical-type experience was measured with the Mystical Experience Questionnaire (MEQ) at the end of the session. Trait mindfulness was measured using the Mindful Attention and Awareness Scale (MAAS) at baseline and 3 months after the psilocybin session. Thirty-two of the participants completed pre-drug [11C]-Cimbi-36 positron emission tomography (PET) to assess 5-HT2AR binding in neocortex and, post-hoc, in the frontolimbic regions amygdala, frontal cortex, and anterior cingulate cortex.

Results

The MAAS score was significantly increased at 3-month follow-up (p = 3.24 × 10-6), a change positively associated with the MEQ score (p = 0.035). Although the association between pre-drug MAAS score and neocortex 5-HT2AR binding was not significant (p = 0.24), post-hoc analyses revealed a significant negative association between MAAS and right amygdala 5-HT2AR binding (pFWER = 0.008).

Conclusion

We here show that lasting changes in trait mindfulness following psilocybin administration are positively associated with intensity of the mystical-type experience, suggesting that the acute phenomenology of psilocybin facilitates a shift in awareness conducive for mindful living. We furthermore show that higher pre-drug trait mindfulness is associated with reduced 5-HT2AR binding in the right amygdala.

The Efficacy of Psychedelic-Assisted Therapy in Managing Post-traumatic Stress Disorder (PTSD): A New Frontier?

Post-traumatic stress disorder (PTSD) is a significant public health concern for which existing therapies are only marginally effective. Indisputably, the primary line of treatment for PTSD is psychotherapy, according to current treatment guidelines. However, PTSD continues to be a chronic condition even after psychotherapy, with high psychiatric and medical illness rates. There is a dire need to search for new compounds and approaches for managing PTSD. The usage of psychedelic substances is a potential new method. This article reviews the efficacy of psychedelic-assisted therapy in treating PTSD and improving patient outcomes. It will examine current research on the topic and evaluate the benefits and drawbacks of different therapies. The current evidence for the use of four different types of psychedelics (3,4-methylenedioxymethamphetamine, ketamine, classical psychedelics, and cannabis) in the treatment of PTSD will be reviewed. It will also include an overview of the therapeutic justification, context of use, and level of evidence available for each drug. Several questions are formulated that could be studied in future research in order to gain a better understanding of the topic.

Neural Mechanisms and Psychology of Psychedelic Ego Dissolution

Neuroimaging studies of psychedelics have advanced our understanding of hierarchical brain organization and the mechanisms underlying their subjective and therapeutic effects. The primary mechanism of action of classic psychedelics is binding to serotonergic 5-HT2A receptors. Agonist activity at these receptors leads to neuromodulatory changes in synaptic efficacy that can have a profound effect on hierarchical message-passing in the brain. Here, we review the cognitive and neuroimaging evidence for the effects of psychedelics: in particular, their influence on selfhood and subject-object boundaries-known as ego dissolution-surmised to underwrite their subjective and therapeutic effects. Agonism of 5-HT2A receptors, located at the apex of the cortical hierarchy, may have a particularly powerful effect on sentience and consciousness. These effects can endure well after the pharmacological half-life, suggesting that psychedelics may have effects on neural plasticity that may play a role in their therapeutic efficacy. Psychologically, this may be accompanied by a disarming of ego resistance that increases the repertoire of perceptual hypotheses and affords alternate pathways for thought and behavior, including those that undergird selfhood. We consider the interaction between serotonergic neuromodulation and sentience through the lens of hierarchical predictive coding, which speaks to the value of psychedelics in understanding how we make sense of the world and specific predictions about effective connectivity in cortical hierarchies that can be tested using functional neuroimaging. SIGNIFICANCE STATEMENT: Classic psychedelics bind to serotonergic 5-HT2A receptors. Their agonist activity at these receptors leads to neuromodulatory changes in synaptic efficacy, resulting in a profound effect on information processing in the brain. Here, we synthesize an abundance of brain imaging research with pharmacological and psychological interpretations informed by the framework of predictive coding. Moreover, predictive coding is suggested to offer more sophisticated interpretations of neuroimaging findings by bridging the role between the 5-HT2A receptors and large-scale brain networks.

Adverse events in clinical treatments with serotonergic psychedelics and MDMA: A mixed-methods systematic review

INTRODUCTION

Small-scale clinical studies with psychedelic drugs have shown promising results for the treatment of several mental disorders. Before psychedelics become registered medicines, it is important to know the full range of adverse events (AEs) for making balanced treatment decisions.

OBJECTIVE

To systematically review the presence of AEs during and after administration of serotonergic psychedelics and 3,4-methyenedioxymethamphetamine (MDMA) in clinical studies.

METHODS

We systematically searched PubMed, PsycINFO, Embase, and ClinicalTrials.gov for clinical trials with psychedelics since 2000 describing the results of quantitative and qualitative studies.

RESULTS

We included 44 articles (34 quantitative + 10 qualitative), describing treatments with MDMA and serotonergic psychedelics (psilocybin, lysergic acid diethylamide, and ayahuasca) in 598 unique patients. In many studies, AEs were not systematically assessed. Despite this limitation, treatments seemed to be overall well tolerated. Nausea, headaches, and anxiety were commonly reported acute AEs across diagnoses and compounds. Late AEs included headaches (psilocybin, MDMA), fatigue, low mood, and anxiety (MDMA). One serious AE occurred during MDMA administration (increase in premature ventricular contractions requiring brief hospitalization); no other AEs required medical intervention. Qualitative studies suggested that psychologically challenging experiences may also be therapeutically beneficial. Except for ayahuasca, a large proportion of patients had prior experience with psychedelic drugs before entering studies.

CONCLUSIONS

AEs are poorly defined in the context of psychedelic treatments and are probably underreported in the literature due to study design (lack of systematic assessment of AEs) and sample selection. Acute challenging experiences may be therapeutically meaningful, but a better understanding of AEs in the context of psychedelic treatments requires systematic and detailed reporting.

Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder: A Randomized Clinical Trial

IMPORTANCE

Although classic psychedelic medications have shown promise in the treatment of alcohol use disorder (AUD), the efficacy of psilocybin remains unknown.

OBJECTIVE

To evaluate whether 2 administrations of high-dose psilocybin improve the percentage of heavy drinking days in patients with AUD undergoing psychotherapy relative to outcomes observed with active placebo medication and psychotherapy.

DESIGN, SETTING, AND PARTICIPANTS

In this double-blind randomized clinical trial, participants were offered 12 weeks of manualized psychotherapy and were randomly assigned to receive psilocybin vs diphenhydramine during 2 day-long medication sessions at weeks 4 and 8. Outcomes were assessed over the 32-week double-blind period following the first dose of study medication. The study was conducted at 2 academic centers in the US. Participants were recruited from the community between March 12, 2014, and March 19, 2020. Adults aged 25 to 65 years with a DSM-IV diagnosis of alcohol dependence and at least 4 heavy drinking days during the 30 days prior to screening were included. Exclusion criteria included major psychiatric and drug use disorders, hallucinogen use, medical conditions that contraindicated the study medications, use of exclusionary medications, and current treatment for AUD.

INTERVENTIONS

Study medications were psilocybin, 25 mg/70 kg, vs diphenhydramine, 50 mg (first session), and psilocybin, 25-40 mg/70 kg, vs diphenhydramine, 50-100 mg (second session). Psychotherapy included motivational enhancement therapy and cognitive behavioral therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was percentage of heavy drinking days, assessed using a timeline followback interview, contrasted between groups over the 32-week period following the first administration of study medication using multivariate repeated-measures analysis of variance.

RESULTS

A total of 95 participants (mean [SD] age, 46 [12] years; 42 [44.2%] female) were randomized (49 to psilocybin and 46 to diphenhydramine). One participant (1.1%) was American Indian/Alaska Native, 3 (3.2%) were Asian, 4 (4.2%) were Black, 14 (14.7%) were Hispanic, and 75 (78.9%) were non-Hispanic White. Of the 95 randomized participants, 93 received at least 1 dose of study medication and were included in the primary outcome analysis. Percentage of heavy drinking days during the 32-week double-blind period was 9.7% for the psilocybin group and 23.6% for the diphenhydramine group, a mean difference of 13.9%; (95% CI, 3.0-24.7; F1,86 = 6.43; P = .01). Mean daily alcohol consumption (number of standard drinks per day) was also lower in the psilocybin group. There were no serious adverse events among participants who received psilocybin.

CONCLUSIONS AND RELEVANCE

Psilocybin administered in combination with psychotherapy produced robust decreases in percentage of heavy drinking days over and above those produced by active placebo and psychotherapy. These results provide support for further study of psilocybin-assisted treatment for AUD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02061293.

Preparing for the Bursting of the Psychedelic Hype Bubble

This Viewpoint presents impediments to the clinical application of psychedelics created by extreme shifts in public perception while advocating further study and encouraging the dispute of claims not supported by available evidence.

Animal Behavior in Psychedelic Research

Psychedelic-assisted psychotherapy holds great promise in the treatment of mental health disorders. Research into 5-hydroxytryptamine 2A receptor (5-HT_2AR) agonist psychedelic compounds has increased dramatically over the past two decades. In humans, these compounds produce drastic effects on consciousness, and their therapeutic potential relates to changes in the processing of emotional, social, and self-referential information. The use of animal behavior to study psychedelics is under debate, and this review provides a critical perspective on the translational value of animal behavior studies in psychedelic research. Acute activation of 5-HT_2ARs produces head twitches and unique discriminative cues, disrupts sensorimotor gating, and stimulates motor activity while inhibiting exploration in rodents. The acute treatment with psychedelics shows discrepant results in conventional rodent tests of depression-like behaviors but generally induces anxiolytic-like effects and inhibits repetitive behavior in rodents. Psychedelics impair waiting impulsivity but show discrepant effects in other tests of cognitive function. Tests of social interaction also show conflicting results. Effects on measures of time perception depend on the experimental schedule. Lasting or delayed effects of psychedelics in rodent tests related to different behavioral domains appear to be rather sensitive to changes in experimental protocols. Studying the effects of psychedelics on animal behaviors of relevance to effects on psychiatric symptoms in humans, assessing lasting effects, publishing negative findings, and relating behaviors in rodents and humans to other more translatable readouts, such as neuroplastic changes, will improve the translational value of animal behavioral studies in psychedelic research. SIGNIFICANCE STATEMENT: Psychedelics like LSD and psilocybin have received immense interest as potential new treatments of psychiatric disorders. Psychedelics change high-order consciousness in humans, and there is debate about the use of animal behavior studies to investigate these compounds. This review provides an overview of the behavioral effects of 5-HT_2AR agonist psychedelics in laboratory animals and discusses the translatability of the effects in animals to effects in humans. Possible ways to improve the utility of animal behavior in psychedelic research are discussed.

Communalistic use of psychoactive plants as a bridge between traditional healing practices and Western medicine: A new path for the Global Mental Health movement

The Global Mental Health (GMH) movement aims to provide urgently needed treatment to those with mental illness, especially in low- and middle-income countries. Due to the complexity of providing mental health services to people from various cultures, there is much debate among GMH advocates regarding the best way to proceed. While biomedical interventions offer some degree of help, complementary approaches should focus on the social/community aspects. Many cultures conduct traditional rituals involving the communal use of psychoactive plants. We propose that these practices should be respected, protected, and promoted as valuable tools with regard to mental health care at the community level. The traditional use of psychoactive plants promotes community engagement and participation, and they are relatively affordable. Furthermore, the worldviews and meaning-making systems of local population are respected. The medical systems surrounding the use of psychoactive plants can be explained in biomedical terms, and many recently published clinical trials have demonstrated their therapeutic potential. Psychoactive plants and associated rituals offer potential benefits as complementary aspects of mental health services. They should be considered as such by international practitioners and advocates of the GMH movement.

Macrodosing to microdosing with psychedelics: Clinical, social, and cultural perspectives

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.

A Research Domain Criteria (RDoC)-Guided Dashboard to Review Psilocybin Target Domains: A Systematic Review

BACKGROUND

Preliminary results from randomized controlled studies as well as identified molecular, cellular, and circuit targets of select psychedelics (e.g., psilocybin) suggest that their effects are transdiagnostic. In this review, we exploit the Research Domain Criteria (RDoC) transdiagnostic framework, to synthesize extant literature on psilocybin.

OBJECTIVE

We aimed to identify RDoC-based effects of psilocybin and vistas for future mechanistic and interventional research.

METHODS

A systematic search in electronic databases (i.e., PubMed, Scopus, PsycINFO, and Web of Science) performed in January and February 2021 identified English articles published between 1990 and 2020 reporting the effects of psilocybin on mental health measures. Data from included articles were retrieved and organized according to the RDoC bio-behavioral matrix and its constituent six main domains, namely: positive valence systems, negative valence systems, cognitive systems, social processes, sensorimotor systems, and arousal and regulatory systems.

RESULTS

The preponderance of research with psilocybin has differentially reported beneficial effects on positive valence systems, negative valence system, and social process domains. The data from the included studies support both short-term (23 assessments) and long-term (15 assessments) beneficial effects of psilocybin on the positive valence systems. While 12 of the extracted outcome measures suggest that psilocybin use is associated with increases in the "fear" construct of the negative valence systems domain, 19 findings show no significant effects on this construct, and seven parameters show lowered levels of the "sustained threat" construct in the long term. Thirty-four outcome measures revealed short-term alterations in the social systems' construct namely, "perception and understanding of self," and "social communications" as well as enhancements in "perception and understanding of others" and "affiliation and attachment". The majority of findings related to the cognitive systems' domain reported dyscognitive effects. There have been relatively few studies reporting outcomes of psilocybin on the remaining RDoC domains. Moreover, seven of the included studies suggest the transdiagnostic effects of psilocybin. The dashboard characterization of RDoC outcomes with psilocybin suggests beneficial effects in the measures of reward, threat, and arousal, as well as general social systems.

CONCLUSIONS

Psilocybin possesses a multi-domain effectiveness. The field would benefit from highly rigorous proof-of-mechanism research to assess the effects of psilocybin using the RDoC framework. The combined effect of psilocybin with psychosocial interventions with RDoC-based outcomes is a priority therapeutic vista.

The use of classic psychedelics among adults: a Danish online survey study

BACKGROUND

Clinical studies report preliminary therapeutic effects of classic psychedelic drugs in several psychiatric conditions and international drug trends show increased use of these compounds. However, the epidemiology of classic psychedelic drug use in Scandinavian countries remains sparsely investigated. To this end, we investigated the patterns of use and the subjectively perceived acute and persisting effects of lysergic acid diethylamide (LSD), psilocybin, N,N-dimethyltryptamine (DMT), and mescaline, among Danish adults.

METHODS

An anonymous online survey with 152 items was conducted using the secure survey web application REDCap. Results were presented descriptively and as comparisons between psychedelic drugs.

RESULTS

Five-hundred participants (30.0% female, mean age 34.5 years) were included. Classic psychedelics were mostly used with therapeutic (28.0%) or spiritual (27.2%) intentions. Sixty-seven per cent used classic psychedelics once a year or less. Most participants (56.4%) preferred using psilocybin. Classic psychedelic use was for some individuals, associated with hazardous use of alcohol (39.4%). Among participants with a psychiatric treatment history, 80.9% reported subjective improvements in symptoms following classic psychedelic use. Participants' most memorable experiences were moderate-to-strong mystical-type experiences (MEQ30 mean ± SD 3.4 ± 1.0; range 1-5) and had positive persisting effects on well-being (mean ± SD 2.1 ± 1.0), social relationships (mean ± SD 1.7 ± 1.2), meaning of life (mean ± SD 1.9 ± 1.1), and mood (mean ± SD 1.8 ± 1.1); range -3 to 3. DMT users experienced significantly greater subjective positive effects.

CONCLUSIONS

Classic psychedelics were mostly used therapeutically or spiritually and had self-reported positive persisting effects, but were also associated with hazardous use of alcohol, among Danish adults. DMT was associated with significantly greater positive effects compared to LSD and psilocybin.

Being no one, being One: The role of ego-dissolution and connectedness in the therapeutic effects of psychedelic experience

Background and aims

Despite promising findings indicating the therapeutic potential of psychedelic experience across a variety of domains, the mechanisms and factors affecting its efficacy remain unclear. The present paper explores this by focusing on two psychedelic states which have been suggested as therapeutically significant in past literature: ego-dissolution and connectedness. The aim of the study is to investigate the impact of ego-dissolution and connectedness on the therapeutic effects of the psychedelic experience.

Methods

The investigation was carried out as a mixed methods systematic review, with the data from four databases analysed thematically and results presented through narrative synthesis.

Results

The analysis and synthesis of findings from 15 unique studies (n = 2,182) indicated that both ego-dissolution and connectedness are associated with a higher chance of improvement following a psychedelic experience. However, there seem to be differences in the way the two experiences affect individuals psychologically. Ego-dissolution appears to trigger psychological change but does not typically exceed the psychedelic experience in its duration, while connectedness can be more sustained and is associated with several positive, potentially therapeutic feelings.

Conclusions

Moreover, the findings of this review have implications for further theory-building about the mechanisms which enable therapeutic effects in psychedelic experience. This in turn might lead to improved models for psychedelic therapy practice. Emphasis on ego-dissolution during the preparation phase and on connectedness during integration is one suggestion presented here, alongside overarching implications for the mental health debate and general practice.

Association between Lifetime Classic Psychedelic Use and Sick Leave in a Population-Based Sample

OBJECTIVES

Absenteeism from work due to illness, and related costs, has increased steadily during the past decades. In recent years, there has been a reemergence of research on the therapeutic effects of classic psychedelics showing associations with both physical and mental health. However, the association between classic psychedelics and sick leave remains unknown. The aim of this study is to investigate the association between lifetime classic psychedelic use and sick leave in the past 30 days among adults in the United States (N = 407,717), using data from the National Survey on Drug Use and Health (2005-2019), weighted to be representative of the US adult population.

METHODS

The primary analysis was conducted using multiple linear regression, controlling for sociodemographic characteristics, risky behavior, and use of other substances.

RESULTS

There was a significant and negative association between lifetime classic psychedelic use and sick leave in the past 30 days (B = -0.09, p < 0.01) when adjusting for all control variables.

CONCLUSION

These findings suggest that classic psychedelics could potentially lead to reduced sick leave and associated costs in the general population, but more research is needed to investigate potential causal pathways of classic psychedelics on sick leave and evaluate possible mechanisms.

Effects of psilocybin versus escitalopram on rumination and thought suppression in depression

BACKGROUND

Major depressive disorder is often associated with maladaptive coping strategies, including rumination and thought suppression.

AIMS

To assess the comparative effect of the selective serotonin reuptake inhibitor escitalopram, and the serotonergic psychedelic psilocybin (COMP360), on rumination and thought suppression in major depressive disorder.

METHOD

Based on data derived from a randomised clinical trial (N = 59), we performed exploratory analyses on the impact of escitalopram versus psilocybin (i.e. condition) on rumination and thought suppression from 1 week before to 6 weeks after treatment inception (i.e. time), using mixed analysis of variance. Condition responder versus non-responder subgroup analyses were also done, using the standard definition of ≥50% symptom reduction.

RESULTS

A time×condition interaction was found for rumination (F(1, 56) = 4.58, P = 0.037) and thought suppression (F(1,57) = 5.88, P = 0.019), with post hoc tests revealing significant decreases exclusively in the psilocybin condition. When analysing via response, a significant time×condition×response interaction for thought suppression (F(1,54) = 8.42, P = 0.005) and a significant time×response interaction for rumination (F(1,54) = 23.50, P < 0.001) were evident. Follow-up tests revealed that decreased thought suppression was exclusive to psilocybin responders, whereas rumination decreased in both responder groups. In the psilocybin arm, decreases in rumination and thought suppression correlated with ego dissolution and session-linked psychological insight.

CONCLUSIONS

These data provide further evidence on the therapeutic mechanisms of psilocybin and escitalopram in the treatment of depression.

Psilocybin use patterns and perception of risk among a cohort of Black individuals with Opioid Use Disorder

Background and aims

There is growing evidence that psilocybin, a serotonergic psychedelic substance, may be useful in the treatment of substance use disorders. However, there is a lack of data on the beliefs and attitudes towards psilocybin amongst Black individuals diagnosed with Opioid Use Disorder (OUD). This study characterized psilocybin use patterns and perception of risk amongst a cohort of Black individuals diagnosed with OUD.

Methods

Using a convenience sampling approach, patients were recruited from an urban methadone treatment program and paid five dollars to complete an anonymous phone-based survey.

Results

Twenty-eight patients participated (mean age 53.8; N = 28; 35.7% female). Most (N = 23; 82.1%) had "heard of" psilocybin mushrooms before taking the survey, but only five (N = 5; 17.8%) had ever used them. More than 80% perceived a risk or were "unsure" of the risk for sixteen of the seventeen items queried about psilocybin. Approximately half (N = 15; 53.6%) were willing to try therapy incorporating psilocybin and half (N = 14; 50%) said they would be more likely to try if it were FDA approved for OUD. Most (N = 18; 64.3%) preferred to stay on methadone treatment alone, 32.1% (N = 9) wanted to try treatment with both psilocybin and methadone, and only one participant opted for psilocybin treatment without methadone.

Conclusion

Many Black individuals with Opioid Use Disorder perceive psilocybin as dangerous and may be hesitant to try psilocybin treatment. Culturally informed treatment models, educational interventions and community outreach programs should be developed to increase racial/ethnic minority representation in psilocybin research and treatment.

Exploratory study of the dose-related safety, tolerability, and efficacy of dimethyltryptamine (DMT) in healthy volunteers and major depressive disorder

There is considerable interest in the therapeutic potential of psychedelic drugs. Dimethyltryptamine (DMT) is a potent, rapid-onset, and short-acting psychedelic drug that has not yet been independently tested for the treatment of depression. The safety, tolerability, and efficacy of intravenous DMT were investigated in treatment-resistant individuals with major depressive disorder (MDD) and healthy controls (HC) in an open-label, fixed-order, dose-escalation (0.1 mg/kg followed by 0.3 mg/kg) exploratory phase 1 study that was conducted in a typical hospital setting with strategic psychoeducation/support, but minimal psychotherapy. Tolerability, safety, cardiovascular function, abuse liability, psychedelic, and psychotomimetic effects, mood, and anxiety were assessed at each dosing session. In addition, depression was measured using the HAMD-17 in MDD participants 1 day after each dosing session. DMT was tolerated by both HC (n = 3) and MDD participants (n = 7) studied; there were no dropouts. HAMD-17 scores decreased significantly (p = 0.017) compared to baseline in MDD participants the day after receiving 0.3 mg/kg DMT (mean difference -4.5 points, 95% CI: -7.80 to -1.20, Hedge's g = 0.75). Adverse events were mostly mild with one self-limited serious event. DMT increased blood pressure, heart rate, anxiety, psychedelic effects, and psychotomimetic effects, which resolved within 20-30 min of injection. There were no dose-related differences in measures of drug reinforcement and abuse liability. In this small exploratory pilot study, intravenous DMT at doses of 0.1 and 0.3 mg/kg was mostly safe and tolerated and may have next-day (rapid) antidepressant effects in patients with treatment-resistant MDD. Further rigorous trials are warranted to replicate these findings and to determine the durability of antidepressant effects.

Acute and long-term effects of psilocybin on energy balance and feeding behavior in mice

Psilocybin and other serotonergic psychedelics have re-emerged as therapeutics for neuropsychiatric disorders, including addiction. Psilocybin induces long-lasting effects on behavior, likely due to its profound ability to alter consciousness and augment neural connectivity and plasticity. Impaired synaptic plasticity in obesity contributes to 'addictive-like' behaviors, including heightened motivation for palatable food, and excessive food seeking and consumption. Here, we evaluate the effects of psilocybin on feeding behavior, energy metabolism, and as a weight-lowering agent in mice. We demonstrate that a single dose of psilocybin substantially alters the prefrontal cortex transcriptome but has no acute or long-lasting effects on food intake or body weight in diet-induced obese mice or in genetic mouse models of obesity. Similarly, sub-chronic microdosing of psilocybin has no metabolic effects in obese mice and psilocybin does not augment glucagon-like peptide-1 (GLP-1) induced weight loss or enhance diet-induced weight loss. A single high dose of psilocybin reduces sucrose preference but fails to counter binge-like eating behavior. Although these preclinical data discourage clinical investigation, there may be nuances in the mode of action of psychedelic drugs that are difficult to capture in rodent models, and thus require human evaluation to uncover.

Inconsistencies between national drug policy and professional beliefs about psychoactive drugs among psychiatrists in the United States

BACKGROUND

Evidence points to an incongruence between international drug policy and expert opinion about safety, abuse potential, and therapeutic potential of specific drugs. However, no prior studies have directly explored psychiatrists' attitudes about the current drug schedule. Therefore, we examined whether American psychiatrists' perceptions of four psychoactive drugs differed from those indicated by their schedules.

METHODS

A quasi-experimental online survey of a convenience sample of psychiatrists in the United States (N=181; Mean age=48.7; Female=35%). Participants were randomized to receive 1-of-4 vignettes, each depicting a depressed patient reporting relief from symptoms after non-prescribed psychoactive drug use (i.e., psilocybin [Schedule I], methamphetamine [SchedII], ketamine [SchedIII], or alprazolam [SchedIV]). Participants responded to questions related to this clinical scenario and then rated the safety, therapeutic, and abuse potentials of these four drugs and alcohol.

RESULTS

There were significant differences by vignette condition in mean likelihood ratings of: warning against engaging in drug use again (p<.01), being concerned about developing a new psychiatric problem (p<.001), being concerned about increased suicide risk (p<.01) and being supportive of further use of this drug as part of the treatment plan (p<.001). Overall, non-prescribed use of methamphetamine and alprazolam was rated more concerning and less acceptable than non-prescribed use of psilocybin and ketamine. Compared to psilocybin and ketamine, participants rated methamphetamine and alprazolam as less safe (p<.001), having less therapeutic potential (p<.001), and having more abuse potential (p<.001). Mean ratings of safety and abuse/therapeutic potential of alprazolam and methamphetamine were equivalent to that of alcohol, and all three were rated more harmful than psilocybin and ketamine.

CONCLUSION

American psychiatrists' perceptions about safety and abuse/therapeutic potentials associated with certain psychoactive drugs were inconsistent with those indicated by their placement in drug schedules. These findings add to a growing consensus amongst experts that the current drug policy is not scientifically coherent.

Postpartum depression: A role for psychedelics?

BACKGROUND

Postpartum depression (PPD) is a major public health concern and has, at its core, a sense of maternal 'disconnection' - from the self, the infant, and the support system. While PPD bears similarities with MDD, there is increasing evidence for its distinct nature, especially with the unique aspect of the mother-infant relationship. Current treatment modalities for PPD, largely based on those used in major depressive disorder (MDD), have low remission rates with emerging evidence for treatment resistance. It is, therefore, necessary to explore alternative avenues of treatment for PPD.

OBJECTIVE

In this narrative review, we outline the potential therapeutic rationale for serotonergic psychedelics in the treatment of PPD, and highlight safety and pragmatic considerations for the use of psychedelics in the postpartum period.

METHODS

We examined the available evidence for the treatment of PPD and the evidence for psychedelics in the treatment of MDD. We explored safety considerations in the use of psychedelics in the postpartum period.

RESULTS

There is increasing evidence for safety, and encouraging signals for efficacy, of psilocybin in the treatment of MDD. Psilocybin has been shown to catalyse a sense of 'reconnection' in participants with MDD. This effect in PPD, by fostering a sense of 'reconnection' for the mother, may allow for improved mood and maternal sensitivity towards the infant, which can positively impact maternal role gratification and the mother-infant relationship.

CONCLUSION

Psychedelic assisted therapy in PPD may have a positive effect on the mother-infant dyad and warrants further examination.

Neural mechanisms underlying psilocybin's therapeutic potential - the need for preclinical in vivo electrophysiology

Psilocybin is a naturally occurring psychedelic compound with profound perception-, emotion- and cognition-altering properties and great potential for treating brain disorders. However, the neural mechanisms mediating its effects require in-depth investigation as there is still much to learn about how psychedelic drugs produce their profound and long-lasting effects. In this review, we outline the current understanding of the neurophysiology of psilocybin's psychoactive properties, highlighting the need for additional preclinical studies to determine its effect on neural network dynamics. We first describe how psilocybin's effect on brain regions associated with the default-mode network (DMN), particularly the prefrontal cortex and hippocampus, likely plays a key role in mediating its consciousness-altering properties. We then outline the specific receptor and cell types involved and discuss contradictory evidence from neuroimaging studies regarding psilocybin's net effect on activity within these regions. We go on to argue that in vivo electrophysiology is ideally suited to provide a more holistic, neural network analysis approach to understand psilocybin's mode of action. Thus, we integrate information about the neural bases for oscillatory activity generation with the accumulating evidence about psychedelic drug effects on neural synchrony within DMN-associated areas. This approach will help to generate important questions for future preclinical and clinical studies. Answers to these questions are vital for determining the neural mechanisms mediating psilocybin's psychotherapeutic potential, which promises to improve outcomes for patients with severe depression and other difficulty to treat conditions.

Psychedelic-Assisted Psychotherapy-A Systematic Review of Associated Psychological Interventions

Modern clinical research on psychedelics is generating interesting outcomes in a wide array of clinical conditions when psychedelic-assisted psychotherapy is delivered to appropriately screened participants and in controlled settings. Still, a number of patients relapse or are less responsive to such treatments. Individual and contextual factors (i.e., set and setting) seem to play a role in shaping the psychedelic experience and in determining clinical outcomes. These findings, coupled with data from literature on the effectiveness of psychotherapy, frame the therapeutic context as a potential moderator of clinical efficacy, highlighting the need to investigate how to functionally employ environmental and relational factors. In this review, we performed a structured search through two databases (i.e., PubMed/Medline and Scopus) to identify records of clinical studies on psychedelics which used and described a structured associated psychotherapeutic intervention. The aim is to construct a picture of what models of psychedelic-assisted psychotherapy are currently adopted in clinical research and to report on their clinical outcomes. Ad-hoc and adapted therapeutic methods were identified. Common principles, points of divergence and future directions are highlighted and discussed with special attention toward therapeutic stance, degree of directiveness and the potential suggestive effects of information provided to patients.

Psychedelic Therapies at the Crossroads of Trauma and Substance Use: Historical Perspectives and Future Directions, Taking a Lead From New Mexico

Post-traumatic stress disorder (PTSD), a common condition with potentially devastating individual, family, and societal consequences, is highly associated with substance use disorders (SUDs). The association between PTSD and SUD is complex and may involve adverse childhood experiences (ACEs), historical and multi-generational traumas, and social determinants of health as well as cultural and spiritual contexts. Current psychosocial and pharmacological treatments for PTSD are only modestly effective, and there is a need for more research on therapeutic interventions for co-occurring PTSD and SUD, including whether to provide integrated or sequential treatments. There is a current resurgence of interest in psychedelics as potential treatment augmentation for PTSD and SUDs with an appreciation of the risks in this target population. This paper reviews the historical perspective of psychedelic research and practices, as well as the intersection of historical trauma, ACEs, PTSD, and SUDs through the lens of New Mexico. New Mexico is a state with high populations of Indigenous and Hispanic peoples as well as high rates of trauma, PTSD, and SUDs. Researchers in New Mexico have been leaders in psychedelic research. Future directions for psychedelic researchers to consider are discussed, including the importance of community-based participatory approaches that are more inclusive and respectful of Indigenous and other minority communities.

Associations between classic psychedelics and nicotine dependence in a nationally representative sample

Tobacco use is the single largest cause of preventable death worldwide, but none of the established treatments aimed at smoking cessation work for a majority of smokers. As such, there is an urgent need for interventions capable of reliably treating nicotine addiction. The use of classic psychedelics has been associated with lower odds of many forms of substance dependence. Here we tested whether lifetime use of classic psychedelics (tryptamine, lysergamide, and phenethylamine) is associated with lower odds of current nicotine dependence. We tested these associations in a sample of 214,505 adult participants in the National Survey on Drug Use and Health (2015–2019) using multivariable logistic regression models. Lifetime psilocybin use was associated with reduced odds of odds of current nicotine dependence (aOR 0.87–0.93). Lifetime use of peyote and mescaline also conferred reduced odds of multiple subdomains of a main nicotine dependence measure (Nicotine Dependence Syndrome Scale [NDSS]) (aOR 0.79–0.91). Conversely, lifetime use of LSD was associated with increased odds of nicotine dependence (aOR 1.17–1.24). Psilocybin, mescaline, and peyote use are associated with lowered odds of nicotine dependence. Experimental studies are needed to establish whether these associations are causal. These results make the case for further research into the efficacy of both tryptamine and phenethylamine psychedelics in promoting smoking cessation.

Models of Psychedelic-Assisted Psychotherapy: A Contemporary Assessment and an Introduction to EMBARK, a Transdiagnostic, Trans-Drug Model

The current standard of care in most uses of psychedelic medicines for the treatment of psychiatric indications includes the provision of a supportive therapeutic context before, during, and after drug administration. A diversity of psychedelic-assisted psychotherapy (PAP) models has been created to meet this need. The current article briefly reviews the strengths and limitations of these models, which are divided into basic support models and EBT-inclusive therapy models. It then discusses several shortcomings both types of models share, including a lack of adequate attention to embodied and relational elements of treatment, and insufficient attention to ethical concerns. The article then introduces the EMBARK model, a transdiagnostic, trans-drug framework for the provision of supportive psychotherapy in PAP clinical trials and the training of study therapists. EMBARK was designed to overcome challenges that prior models have had in conceptualizing therapeutic change in psychedelic treatment, incorporating elements of non-psychedelic evidence-based therapies, incorporating therapists' prior skills and clinical orientations, delimiting therapist interventions for research standardization, and determining specific factors that contribute to treatment outcomes. The article explains EMBARK's six clinical domains, which represent parallel conceptualizations of how therapists may support therapeutic benefit in PAP treatment, and its four care cornerstones, which reflect therapists' broad ethical responsibility to participants. The article describes how these elements of the model come together to structure and inform therapeutic interventions during preparation, medicine, and integration sessions. Additionally, the article will discuss how EMBARK therapist training is organized and conducted. Finally, it will demonstrate the broad applicability of EMBARK by describing several current and upcoming PAP clinical trials that have adopted it as the therapeutic frame.

Optimization through a Box-Behnken Experimental Design of the Microwave-Assisted Extraction of the Psychoactive Compounds in Hallucinogenic Fungi (Psylocibe cubensis)

Hallucinogenic fungi, mainly those from the Psilocybe genus, are being increasingly consumed even though there is no control on their culture conditions. Due to the therapeutic potential as antidepressants and anxiolytics of the alkaloids that they produce (psilocin and psilocybin), some form of control on their production would be highly recommended. Prior to identifying their optimal culture condition, a methodology that allows their study is required. Microwave-assisted extraction method (MAE) is a technique that has proven its efficiency to extract different compounds from solid matrices. For this reason, this study intends to optimize a MAE method to extract the alkaloids found in Psylocibe cubensis. A surface-response Box-Behnken design has been employed to optimize such extraction method and significantly reduce time and other resources in the extraction process. Based on the Box-Behnken design, 50 °C temperature, 60% methanol as extraction solvent, 0.6 g:10 mL sample mass:solvent ratio and 5 min extraction time, were established as optimal conditions. These mild conditions, combined with a rapid and efficient UHPLC analysis result in a practical and economical methodology for the extraction of psilocin and psilocybin from Psylocibe cubensis.

Drug-drug interactions between psychiatric medications and MDMA or psilocybin: a systematic review

RATIONALE & OBJECTIVES

 ± 3,4-Methylenedioxymethamphetamine (MDMA) and psilocybin are currently moving through the US Food and Drug Administration's phased drug development process for psychiatric treatment indications: posttraumatic stress disorder and depression, respectively. The current standard of care for these disorders involves treatment with psychiatric medications (e.g., selective serotonin reuptake inhibitors), so it will be important to understand drug-drug interactions between MDMA or psilocybin and psychiatric medications.

METHODS

In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we queried the MEDLINE database via PubMed for publications of human studies in English spanning between the first synthesis of psilocybin (1958) and December 2020. We used 163 search terms containing 22 psychiatric medication classes, 135 specific psychiatric medications, and 6 terms describing MDMA or psilocybin.

RESULTS

Forty publications were included in our systematic review: 26 reporting outcomes from randomized controlled studies with healthy adults, 3 epidemiologic studies, and 11 case reports. Publications of studies describe interactions between MDMA (N = 24) or psilocybin (N = 5) and medications from several psychiatric drug classes: adrenergic agents, antipsychotics, anxiolytics, mood stabilizers, NMDA antagonists, psychostimulants, and several classes of antidepressants. We focus our results on pharmacodynamic, physiological, and subjective outcomes of drug-drug interactions.

CONCLUSIONS

As MDMA and psilocybin continue to move through the FDA drug development process, this systematic review offers a compilation of existing research on psychiatric drug-drug interactions with MDMA or psilocybin.

Assessing the risk-benefit profile of classical psychedelics: a clinical review of second-wave psychedelic research

RATIONALE

A broad reassessment of the potential benefits of psychedelic drugs has led to the initiation of multiple major clinical trials in an effort to advance their status to become FDA-approved medications, as well as local legislative efforts to legalize or decriminalize their use.

OBJECTIVES

To use recently published data to assess potential risks and benefits of psychedelic drugs as therapeutics, as well as to synthesize what is currently known in order to generate fruitful future research directions.

METHODS

A review of studies conducted since 1991 identified 14 clinical trials of classical psychedelics, including 11 of psilocybin (N = 257 participants), 1 of lysergic acid diethylamide (N = 12 participants), and 2 of ayahuasca (N = 46 participants). Other published studies (e.g., of healthy volunteers, survey studies, case reports, neuroimaging) were also considered for review.

RESULTS

Published studies since 1991 largely support the hypothesis that small numbers of treatments with psychedelic-assisted psychotherapy can offer significant and sustained alleviation to symptoms of multiple psychiatric conditions. No serious adverse events attributed to psychedelic therapy have been reported. Existing studies have several limitations, including small sample sizes, inherent difficulty in blinding, relatively limited follow-up, and highly screened treatment populations.

CONCLUSIONS

Substantial data have been gathered in the past 30 years suggesting that psychedelics are a potent treatment for a variety of common psychiatric conditions, though the ideal means of employing these substances to minimize adverse events and maximize therapeutic effects remains controversial. Unique factors related to study design are vital for clinical researchers in the field to address.

Effects of the 5-HT2A receptor antagonist volinanserin on head-twitch response and intracranial self-stimulation depression induced by different structural classes of psychedelics in rodents

BACKGROUND

Clinical studies suggest that psychedelics exert robust therapeutic benefits in a number of psychiatric conditions including substance use disorder. Preclinical studies focused on safety and efficacy of these compounds are necessary to determine the full range of psychedelics' effects.

OBJECTIVES

The present study explores the behavioral pharmacology of structurally distinct psychedelics in paradigms associated with serotonin 2A receptor (5-HT_2AR) activation and behavioral disruption in two rodent models. Utilizing the selective 5-HT_2AR antagonist volinanserin, we aimed to provide further pharmacological assessment of psychedelic effects in rodents.

METHODS

We compared volinanserin (0.0001-0.1 mg/kg) antagonism of the phenethylamine 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 1.0 mg/kg) and the ergoline lysergic acid diethylamide (LSD, 0.32 mg/kg) in preclinical assays predictive of hallucinations (head-twitch response or HTR in mice) and behavioral disruption (intracranial self-stimulation or ICSS in rats). Volinanserin antagonism of the phenethylamine mescaline, the tryptamine psilocybin, and the k-opioid receptor agonist salvinorin A was also evaluated in the rat ICSS assay.

RESULTS

Volinanserin had similar potency, effectiveness, and time-course to attenuate DOI-induced HTR in mice and ICSS depression in rats. Volinanserin completely blocked LSD-induced HTR in mice, but not LSD-induced ICSS depression in rats. Volinanserin also reversed ICSS depression by mescaline, but it was only partially effective to reduce the effects of psilocybin, and it exacerbated ICSS depression by salvinorin A.

CONCLUSION

Although hallucination-related HTR behavior induced by phenethylamine, ergoline, and tryptamine psychedelics appears to be 5-HT_2AR-mediated, the receptor(s) responsible for behavioral disruptive effects may differ among these three structural classes.

Ayahuasca and tobacco smoking cessation: results from an online survey in Brazil

RATIONALE

Smoking-related disease is a major problem globally. Effective smoking cessation treatments are however limited. Increasing evidence suggests that psychedelics have potential as treatments for substance use disorders and may therefore prove an option in aiding smoking cessation.

OBJECTIVES

To establish which factors predict smoking cessation in people who reported quitting or reducing smoking following ayahuasca consumption.

METHODS

A retrospective cross-sectional mixed-method study (quantitative and qualitative design) was undertaken using data from an online survey evaluating peoples' experiences before and after drinking ayahuasca. Multivariate logistic regression was performed with smoking condition (cessation or reduction/relapse) as a dependent variable and demographics, smoking, ayahuasca-related variables and the mystical experience (MEQ30) as predicting factors.

RESULTS

A total of 441 responses were grouped according to self-reported smoking status: cessation (n = 305) or reduction/relapse (n = 136) smoking. Logistic regression showed that mystical experience (OR: 1.03; 95% CI [1.00-1.05]) and frequency of ayahuasca intake (OR: 2.16[1.00-4.70]) were protective factors, while positive mood (measured by the MEQ30) during the ayahuasca experience was a risk factor (OR: 0.91[0.85-0.97]). Qualitative thematic analysis identified eight themes (e.g. acquired awareness, spiritual experience, increased motivation) related to the ayahuasca experience and the process of smoking cessation/reduction.

CONCLUSIONS

Our results suggest that ayahuasca could be used as a potential tool for smoking cessation, and that effects may be mediated by mystical experience. Given the current burden of smoking-related disease and the limited treatment options, studies are needed to investigate the efficacy of psychedelics in smoking cessation.

Effects of ayahuasca and its alkaloids on substance use disorders: an updated (2016-2020) systematic review of preclinical and human studies

Ayahuasca is a hallucinogenic/psychedelic traditionally used for ritual and therapeutic purposes. One such therapeutic use is related to Substance Use Disorders (SUDs). A previous systematic review of preclinical and human studies published until 2016 suggested that ayahuasca and its alkaloids have therapeutic effects in the treatment of SUDs. To conduct an update of this previous review. A systematic review of quantitative studies which analyzed the effects of ayahuasca and its alkaloids on drug use (primary outcome) and other measures (secondary outcomes) related to SUDs was conducted, including articles from 2016 to 2020. Nine studies (four preclinical, five observational) were included in the review. Preclinical studies in rodents reported reductions in amphetamine self-administration and anxiety, and in alcohol- and methylphenidate-induced conditioned place preference. Observational studies among healthy ritual ayahuasca users and patients with SUDs reported reductions in drug use, anxiety, and depression, and increases in quality of life and well-being. We replicated the findings of the previous review suggesting that ayahuasca and its alkaloids have therapeutic effects in the treatment of SUDs. However, translation of preclinical data to humans is limited, observational studies do not allow us to infer causality, and there is a lack of standardization on ayahuasca doses. Although promising, randomized, controlled trials are needed to better elucidate these results. The PROSPERO ID for this study is CRD42020192046.

Great Expectations: recommendations for improving the methodological rigor of psychedelic clinical trials

RATIONALE

Psychedelic research continues to garner significant public and scientific interest with a growing number of clinical studies examining a wide range of conditions and disorders. However, expectancy effects and effective condition masking have been raised as critical limitations to the interpretability of the research.

OBJECTIVE

In this article, we review the many methodological challenges of conducting psychedelic clinical trials and provide recommendations for improving the rigor of future research.

RESULTS

Although some challenges are shared with psychotherapy and pharmacology trials more broadly, psychedelic clinical trials have to contend with several unique sources of potential bias. The subjective effects of a high-dose psychedelic are often so pronounced that it is difficult to mask participants to their treatment condition; the significant hype from positive media coverage on the clinical potential of psychedelics influences participants' expectations for treatment benefit; and participant unmasking and treatment expectations can interact in such a way that makes psychedelic therapy highly susceptible to large placebo and nocebo effects. Specific recommendations to increase the success of masking procedures and reduce the influence of participant expectancies are discussed in the context of study development, participant recruitment and selection, incomplete disclosure of the study design, choice of active placebo condition, as well as the measurement of participant expectations and masking efficacy.

CONCLUSION

Incorporating the recommended design elements is intended to reduce the risk of bias in psychedelic clinical trials and thereby increases the ability to discern treatment-specific effects of psychedelic therapy.

If the doors of perception were cleansed, would chronic pain be relieved? Evaluating the benefits and risks of psychedelics

Psychedelic substances have played important roles in diverse cultures, and ingesting various plant preparations to evoke altered states of consciousness has been described throughout recorded history. Accounts of the subjective effects of psychedelics typically focus on spiritual and mystical-type experiences, including feelings of unity, sacredness, and transcendence. Over the past two decades, there has been increasing interest in psychedelics as treatments for various medical disorders, including chronic pain. Although concerns about adverse medical and psychological effects contributed to their controlled status, contemporary knowledge of psychedelics suggests that risks are relatively rare when patients are carefully screened, prepared, and supervised. Clinical trial results have provided support for the effectiveness of psychedelics in different psychiatric conditions. However, there are only a small number of generally uncontrolled studies of psychedelics in patients with chronic pain (e.g., cancer pain, phantom limb pain, migraine, and cluster headache). Challenges in evaluating psychedelics as treatments for chronic pain include identifying neurobiologic and psychosocial mechanisms of action and determining which pain conditions to investigate. Truly informative proof-of-concept and confirmatory randomized clinical trials will require careful selection of control groups, efforts to minimize bias from unblinding, and attention to the roles of patient mental set and treatment setting. Perspective: There is considerable promise for the use of psychedelic therapy for pain, but evidence-based recommendations for the design of future studies are needed to ensure that the results of this research are truly informative.

Psychedelics and Psychotherapy: Cognitive-Behavioral Approaches as Default

The acute subjective effects of psychedelics are responsive to users' expectations and surroundings (i.e., "set and setting"). Accordingly, a great deal of thought has gone into designing the psychosocial context of psychedelic administration in clinical settings. But what theoretical paradigms inform these considerations about set and setting? Here, we describe several historical, sociological influences on current psychedelic administration in mainstream European and American clinical research settings, including: indigenous practices, new age spirituality from the 1960s, psychodynamic/psychoanalytic approaches, and cognitive-behavioral approaches. We consider each of these paradigms and determine that cognitive-behavioral therapies, including newer branches such as acceptance and commitment therapy (ACT), have the strongest rationale for psychedelic-assisted psychotherapy going forward. Our primary reasons for advocating for cognitive-behavioral approaches include, (1) they avoid issues of cultural insensitivity, (2) they make minimal speculative assumptions about the nature of the mind and reality, (3) they have the largest base of empirical support for their safety and effectiveness outside of psychedelic therapy. We then propose several concepts from cognitive-behavioral therapies such as CBT, DBT, and ACT that can usefully inform the preparation, session, and integration phases of psychedelic psychotherapy. Overall, while there are many sources from which psychedelic psychotherapy could draw, we argue that current gold-standard, evidence-based psychotherapeutic paradigms provide the best starting point in terms of safety and efficacy.

The psychological processes of classic psychedelics in the treatment of depression: a systematic review protocol

BACKGROUND

There is currently renewed interest in the use of psychedelic therapy in the treatment of psychiatric disorders, including depression. The proposed systematic review will aim to identify, evaluate and summarise the psychological processes of change underlying psychedelic therapy for depression in the current literature and consider the implications these processes may have on the psychotherapy component of treatment.

METHODS

Scopus, PsycINFO, PubMed and Web of Science databases will be searched using relevant terms. Studies will be included if they discuss the use of a classic psychedelic to treat depression symptomology in an adult population and report or propose psychological processes responsible for depression symptom change. Two authors will independently screen articles, complete quality assessment tools and conduct data extraction. Empirical and non-empirical research will be extracted and synthesised separately. A narrative synthesis approach will be used to report psychological processes identified in the literature.

DISCUSSION

This systematic review will be the first to collate available evidence on the psychological processes associated with psychedelic therapy for depression. The preliminary nature of this research field is expected to result in the review having several limitations, namely heterogeneity between studies and the inclusion of limited empirical research. We intend for this review to present the current state of the literature, identify gaps and generate candidate variables that warrant further investigation.

SYSTEMATIC REVIEW

PROSPERO CRD42020197202.

Human behavioral pharmacology of psychedelics

The past decade has witnessed a rapid growth of research on the basic science and clinical understanding of psychedelics. This chapter provides an overview of the human behavioral pharmacology of psychedelics focusing on three prototypic classic psychedelics-psilocybin, lysergic acid diethylamide (LSD), and dimethyltryptamine (DMT). A brief historical overview of the classic psychedelics and naming and drug classification is first specified. Next, special considerations in the conduct of human behavioral pharmacology work with psychedelics is described including the role of set and setting, mystical experience measurement, the use of effective blinding and placebos, and the abuse liability of psychedelics. Following, a description of the subjective, physiological, and clinical effects of psilocybin, LSD, and DMT is provided. This body of work clearly documents a unique and complex collection of subjective effects following psychedelic use, both during acute drug administration and as related to long-term behavior change following use. Clinical research demonstrates potential therapeutic utility with early phase clinical trials showing positive and enduring effects in many difficult-to-treat conditions including treatment-resistant depression, alcohol use disorder, and cigarette smoking. Future work in this newly reemerged field is needed to reveal mechanisms of behavior change in psychedelic drug action. Behavioral pharmacology is ultimately well served to provide this direction answering questions at the intersection of environment and pharmacology.