Human hallucinogen research: guidelines for safety

At-home, telehealth-supported ketamine treatment for depression: Findings from longitudinal, machine learning and symptom network analysis of real-world data

BACKGROUND

Improving safe and effective access to ketamine therapy is of high priority given the growing burden of mental illness. Telehealth-supported administration of sublingual ketamine is being explored toward this goal.

METHODS

In this longitudinal study, moderately-to-severely depressed patients received four doses of ketamine at home over four weeks within a supportive digital health context. Treatment was structured to resemble methods of therapeutic psychedelic trials. Patients receiving a second course of treatment were also examined. Symptoms were assessed using the Patient Health Questionnaire (PHQ-9) for depression. We conducted preregistered machine learning and symptom network analyses to investigate outcomes (osf.io/v2rpx).

RESULTS

A sample of 11,441 patients was analyzed, demonstrating a modal antidepressant response from both non-severe (n = 6384, 55.8 %) and severe (n = 2070, 18.1 %) baseline depression levels. Adverse events were detected in 3.0-4.8 % of participants and predominantly neurologic or psychiatric in nature. A second course of treatment helped extend improvements in patients who responded favorably to initial treatment. Improvement was most strongly predicted by lower depression scores and age at baseline. Symptoms of Depressed mood and Anhedonia sustained depression despite ongoing treatment.

LIMITATIONS

This study was limited by the absence of comparison or control groups and lack of a fixed-dose procedure for ketamine administration.

CONCLUSIONS

At-home, telehealth-supported ketamine administration was largely safe, well-tolerated, and associated with improvement in patients with depression. Strategies for combining psychedelic-oriented therapies with rigorous telehealth models, as explored here, may uniquely address barriers to mental health treatment.

Stutterers' experiences on classic psychedelics: A preliminary self-report study

Stuttering poses challenges to social, occupational, and educational aspects of life. Traditional behavioral therapies can be helpful but effects are often limited. Pharmaceutical treatments have been explored but there are no FDA-approved treatments for stuttering. Interest has grown in the potential use of classic psychedelics, including psilocybin and LSD, which have shown effectiveness in treating disorders with similar symptoms (e.g., anxiety, depression, PTSD). The potential effects of psychedelics on stuttering have not been explored. We conducted a preliminary investigation of self-identified stutterers who report their experiences taking classic psychedelics on the online messaging forum, Reddit. We qualitatively analyzed 114 publicly available posts, extracting meaningful units and assigning descriptor codes inductively. We then deductively organized responses into an established framework of psychedelics which includes behavioral, emotional, cognitive, belief-based, and social effects. These effects were subsequently grouped under organizing themes (positive, negative, neutral). Descriptive statistics revealed that the majority of users (74.0%) reported positive overall short-term effects particularly related to behavioral and emotional change (e.g., reduced stuttering and anxiety), but negative (9.6%), mixed (positive and negative; 4.8%), and neutral overall experiences (11.6%) were also reported. The results support the possibility that psychedelics may impact stuttering, but caution must be applied in their interpretation given the entirely uncontrolled research setting and potential adverse health effects of psychedelics as reported elsewhere. While these results do not encourage the use of psychedelics by stutterers, they suggest that future work could examine the impact of psychedelics on stuttering under supervised and in clinically controlled settings.

Guiding Through Challenging Psychedelic Experiences and "Bad Trips"

Psychedelic substances have gained recognition for their therapeutic potential, but they also present challenges, with individuals occasionally experiencing distressing episodes referred to as challenging experiences or, in the recreational setting, "bad trips". Trial therapists and physicians, but also healthcare professionals in emergency rooms, need a comprehensive strategy to effectively manage these cases. Three case reports are presented to underline the problem and propose strategies for handling these situations. Finally, this article outlines a stepwise approach, encompassing helpful interventions, supportive care, and rescue medication, to ensure the well-being of individuals undergoing challenging psychedelic experiences and prevent further complications and long-term harm.

The role of psilocybin in depressive disorders

Depression is a serious psychiatric disorder with a high incidence of morbidity and mortality and psilocybin with psychotherapy has emerged as a promising potential in the treatment of depressive disorders. A review of psilocybin use in patients with depressive disorders is presented.A search was conducted investigating the use of psilocybin in patients with depressive disorders and treatment resistant depression via PubMed/MEDLINE, EMBASE, and Google Scholar in October 2023; all publication types were permitted and limited for English-language. Keyword search terms included: "psilocybin" or "psychedelics" and "depression", or "major depressive disorder", or "treatment-resistant depression". Controlled and uncontrolled clinical trials utilizing psilocybin with psychological support for major depressive disorder and treatment-resistant depression, as well as in patients with depression and cancer related anxiety have demonstrated immediate and sustained antidepressant and anxiolytic effects. Psilocybin has a favorable safety profile and was well-tolerated in clinical trials. Psilocybin's abuse potential is low and clinical research suggests the potential of psilocybin to produce rapid and lasting antidepressant effects up to 12 months post-treatment. Psilocybin may offer a valuable contribution as an option to the currently available pharmacological and psychotherapeutic agents for patients with major depressive disorders, treatment-resistant depression as well as for patients with depression and comorbid terminal cancer. Future studies are needed to demonstrate these findings and any synergistic interaction between psilocybin and the psychological support offered to patients during sessions.

Validation of the Swiss Psychedelic Side Effects Inventory: Standardized assessment of adverse effects in studies of psychedelics and MDMA

INTRODUCTION

Studies of psychedelic-assisted therapy with LSD, psilocybin, MDMA, and related substances show clinical promise but inadequately assess side effects. Measuring side effects is challenging because they are not always easily differentiated from treatment effects or disease symptoms and show high heterogeneity, variable duration and impact, and sensitivity to context. A systematic questionnaire describing important characteristics of side effects of psychedelics and MDMA would greatly improve on previous methods. We aimed to create a standardized tool for recording clinically relevant side effects of psychedelics and MDMA, including their severity, duration, impact, and treatment-relatedness.

METHODS

We constructed the Swiss Psychedelic Side Effects Inventory (SPSI) based on insights from previous research. It was pilot tested in 145 participants from three studies. Structured feedback from an expert panel was used to improve validity and feasibility.

RESULTS

The final SPSI contains 32 side effects and standardized follow-up questions about their severity, impact, treatment-relatedness, and duration. It is compatible with any study design and can be administered as an interview or self-report at any timepoint after treatment with psychedelics or MDMA.

LIMITATIONS

The SPSI omits relatively unimportant side effects for brevity's sake, though space for additional symptoms is given. Future studies are needed to confirm its validity in different contexts.

CONCLUSIONS

The SPSI is available in English and German for collecting systematic data on side effects from psychedelics and MDMA. This information is vital for improving clinical decisions, informed consent, and patient safety.

Comparison between Single-Dose and Two-Dose Psilocybin Administration in the Treatment of Major Depression: A Systematic Review and Meta-Analysis of Current Clinical Trials

Current pharmacological treatments for major depressive disorder (MDD) are often only partially effective, with many patients experiencing no significant benefit, leading to treatment-resistant depression (TRD). Psilocybin, a classical serotonergic psychedelic, has emerged as a notable emerging treatment for such disorders. The aim of this systematic review and meta-analysis is to summarize and discuss the most recent evidence about the therapeutic effects of single-dose and two-dose psilocybin administration on the severity of depressive symptoms, as well as compare the efficacy of these interventions among patients with a primary diagnosis of MDD or TRD. Articles were collected from EBSCOhost and PubMed following the PRISMA guidelines, yielding 425 articles with 138 duplicates. After screening 287 records, 12 studies met the eligibility criteria and were included in the review. A quantitative analysis of the studies indicates that psilocybin is highly effective in reducing depressive symptoms severity among patients with primary MDD or TRD. Both single-dose and two-dose psilocybin treatments significantly reduced depressive symptoms severity, with two-dose administration sometimes yielding more pronounced and lasting effects. However, it is unclear if this was solely due to dosage or other factors. Future research should include standardized trials comparing these dosing strategies to better inform clinical practice.

Rapid effects of tryptamine psychedelics on perceptual distortions and early visual cortical population receptive fields

N, N-dimethyltryptamine (DMT) is a psychedelic tryptamine acting on 5-HT2A serotonin receptors, which is associated with intense visual hallucinatory phenomena and perceptual changes such as distortions in visual space. The neural underpinnings of these effects remain unknown. We hypothesised that changes in population receptive field (pRF) properties in the primary visual cortex (V1) might underlie visual perceptual experience. We tested this hypothesis using magnetic resonance imaging (MRI) in a within-subject design. We used a technique called pRF mapping, which measures neural population visual response properties and retinotopic maps in early visual areas. We show that in the presence of visual effects, as documented by the Hallucinogen Rating Scale (HRS), the mean pRF sizes in V1 significantly increase in the peripheral visual field for active condition (inhaled DMT) compared to the control. Eye and head movement differences were absent across conditions. This evidence for short-term effects of DMT in pRF may explain perceptual distortions induced by psychedelics such as field blurring, tunnel vision (peripheral vision becoming blurred while central vision remains sharp) and the enlargement of nearby visual space, particularly at the visual locations surrounding the fovea. Our findings are also consistent with a mechanistic framework whereby gain control of ongoing and evoked activity in the visual cortex is controlled by activation of 5-HT2A receptors.

The association between diverse psychological protocols and the efficacy of psilocybin-assisted therapy for clinical depressive symptoms: a Bayesian meta-analysis

Objective

Psilocybin-assisted therapy has shown promising efficacy on clinical depressive symptoms. However, diverse psychological support or psychotherapy was performed with psilocybin treatment. This study aimed to explore the association of psychological protocols with the efficacy of psilocybin-assisted therapy for depressive symptoms.

Method

Five major databases were systemic searched for clinical trials addressing psilocybin-assisted therapy for patients with clinical depressive symptoms. A Bayesian random-effects meta-analysis and meta-regression were performed. The effect size was mean difference (with 95% credible interval) measured by 17-Item Hamilton Depression Rating Scale.

Results

There were 10 eligible studies including 515 adult patients with clinically diagnosed depression. The psychological protocols could be categorized into four types: (i) manualized directive psychotherapy(k=1); (ii) manualized nondirective psychological support(k=3), (iii) non-manualized nondirective psychological support(k=5); and (iv) non-manualized supportive psychotherapy(k=1). The pooled standard mean difference of psilocybin-assisted therapy was 10.08 (5.03-14.70).

Conclusion

Compared with manualized nondirective psychological support, the other three psychological approaches did not differ significantly. The improvement of depressive symptoms was not associated with the psychological protocols in adult patients receiving psilocybin-assisted therapy.

Systemic review registration

Open Science Framework: identifier (osf.io/3YUDV).

Expert opinions on implementation of MDMA-assisted therapy in Europe: critical appraisal towards training, clinical practice, and regulation

Introduction: The positive results of MDMA from Phase 2 and 3 clinical trials in MDMA-assisted therapy (MDMA-AT) for the treatment of post-traumatic stress disorder (PTSD) call for a critical evaluation of its regulatory status within the European mental healthcare system. This is driven by the recent submission of MDMA-AT for FDA approval in the United States. Unless coordinated efforts in the European regulatory landscape start, there may be potential divergences in national regulatory strategies. Gaining insights from researchers and clinicians involved in the application of MDMA-AT may be useful in guiding the discussion of factors involved in its implementation.Method: A comprehensive invitation-only survey was sent to researchers and clinicians involved in MDMA-AT clinical trials and contributors to the scientific literature on MDMA-AT from around the globe. This study aimed to collect opinions on clinical practices, training, and regulation worldwide, examining the global best practices and pitfalls to outline strategies for possible European implementation of MDMA-AT.Results: The survey, which included responses from 68 experts, yielded a range of opinions where a large majority endorsed the need for training and standardization, emphasizing equity and access, stressing impediments in the national approval processes, and reflecting critically on anticipated spill-over effects of MDMA-AT in clinical settings.Conclusion: The experts highlight the need for science-informed policy development, active regulatory involvement, and international cooperation to incorporate MDMA-AT into the European mental healthcare system in general and the treatment of PTSD in particular. The study emphasizes the importance of ongoing research, open professional discourse, and collaborative engagement to facilitate MDMA-AT's ethical and effective implementation.

Psilocybin and chronic neuropathic pain: a systematic review

BACKGROUND/IMPORTANCE

Chronic pain affects many people globally, requiring alternative management strategies. Psilocybin is gaining attention for its potential in chronic pain management despite being classified as Schedule I.

OBJECTIVE

This systematic review critically evaluates the evidence for psilocybin, a Schedule I substance, in the treatment of chronic pain. The exact purpose of the review is to assess the impact of psilocybin on chronic pain relief, focusing on dosing protocols, treated conditions, and patient outcomes.

EVIDENCE REVIEW

A comprehensive review of PubMed, CINAHL, Web of Science, Cochrane Library, and EMBASE was conducted up to January 2024. Eligibility criteria included studies evaluating psilocybin for chronic pain management. The risk of bias was assessed using the MASTER (MethodologicAl STandards for Epidemiological Research) scale, and the strength of evidence was graded using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation).

FINDINGS

The review identified 28 relevant studies focusing on dosing, treated conditions, and outcomes. The majority of the included studies (76.2%) were of low or very low quality. Several studies with moderate-to-low-quality evidence utilized a 0.14 mg/kg dosing protocol. The findings suggest promise for the use of psilocybin in chronic pain relief, though the quality of evidence is generally low.

CONCLUSIONS

The current research shows potential for psilocybin as a treatment option for chronic pain relief. However, methodological issues and a lack of high-quality evidence underscore the need for further investigations with standardized protocols. Despite these limitations, the potential for psilocybin in chronic pain management is encouraging.

PROSPERO REGISTRATION NUMBER

CRD42023493823.

The Global Psychedelic Survey: Consumer characteristics, patterns of use, and access in primarily anglophone regions around the world

OBJECTIVES

Despite advancements in policies governing psychedelic substances globally, our understanding of real-world psychedelic use and its variations across international jurisdictions remains limited. We implemented the Global Psychedelic Survey (GPS) to capture information about psychedelic consumer characteristics, access, and usage patterns around the world.

METHODS

The GPS was administered online in Spring 2023 to English-speaking adults (≥21 years) who use(d) psychedelics. We categorized survey responses into major catchment regions (Canada/US, Europe/UK, Australia/NZ, All Other). We used descriptive and bivariable statistics to characterize consumers' socio-demographic characteristics, psychedelic access sources, and usage patterns. We examined regional differences in psychedelic use patterns using multinomial logistic regression.

RESULTS

We analyzed 6379 responses from 85 countries including Canada/US (n = 4434), Europe/UK (n = 771), Australia/NZ (n = 864), and Other (n = 310). Psilocybin, LSD, and MDMA were the most used psychedelics and personal growth was the most common use motive across all catchments. There were significant regional differences in psychedelic use patterns, including types of psychedelics used (e.g., less ibogaine use in Europe/UK and Australia/NZ relative to Canada/US), frequency of use (e.g., lower frequency use in Australia/NZ relative to Canada/US), motivations for use (e.g., less therapeutic use in Europe/UK and Other relative to Canada/US), and types of dosing regimens (e.g., more "micro"-dosing in Canada/US).

DISCUSSION

In this large sample of adult psychedelic consumers from regions around the world, infrequent psychedelic use centered around life enhancement was common. Respondents indicated preference for legal access via quality-controlled sources. Jurisdictional differences in access and usage patterns likely reflect region-specific regulations and traditional practices. Further research should explore opportunities to increase representation of non-White respondents in psychedelic research via translation of studies into several languages and incorporation of culturally reflective, community-based study development.

Phase 1, placebo-controlled, single ascending dose trial to evaluate the safety, pharmacokinetics and effect on altered states of consciousness of intranasal BPL-003 (5-methoxy-N,N-dimethyltryptamine benzoate) in healthy participants

AIMS

To investigate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of BPL-003, a novel intranasal benzoate salt formulation of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), in healthy participants.

METHODS

In all, 44 psychedelic-naïve participants enrolled in the double-blind, placebo-controlled single ascending dose study (1-12 mg BPL-003). Concentrations of 5-MeO-DMT and its pharmacologically active metabolite, bufotenine, were determined in plasma and urine. PD endpoints included subjective drug intensity (SDI) rating, the Mystical Experience Questionnaire (MEQ-30) and the Ego Dissolution Inventory (EDI).

RESULTS

BPL-003 was well tolerated at doses up to 12 mg. There were no serious adverse events (AEs), and most AEs were mild; the most common being nasal discomfort, nausea, headache and vomiting. 5-MeO-DMT was rapidly absorbed and eliminated; the median time to peak plasma concentration was approximately 8-10 min and the mean terminal elimination half-life was <27 min. 5-MeO-DMT systemic exposure increased approximately dose-proportionally, while plasma bufotenine concentrations and urinary excretion of 5-MeO-DMT and bufotenine were negligible. The intensity of the SDI ratings was associated with plasma 5-MeO-DMT concentrations. MEQ-30 and EDI scores generally increased with the BPL-003 dose; 60% of participants had a 'complete mystical experience' at 10 and 12 mg doses. Profound and highly emotional consciousness-altering effects were observed with BPL-003, with a rapid onset and short-lasting duration.

CONCLUSION

The novel intranasal formulation of BPL-003 was well tolerated with dose-proportional increases in PK and PD effects. The short duration of action and induction of mystical experiences suggest clinical potential, warranting further trials.

CLINICAL TRIAL REGISTRATION

NCT05347849.

Content analysis of Reddit posts about coadministration of selective serotonin reuptake inhibitors and psilocybin mushrooms

RATIONALE

Treatments with the serotonergic psychedelic psilocybin are being investigated for multiple neuropsychiatric disorders. Because many patients with these disorders use selective serotonin reuptake inhibitors (SSRIs), understanding interactions between psilocybin and SSRIs is critical for evaluating the safety, efficacy, and scalability of psilocybin-based treatments. Current knowledge about these interactions is limited, as most clinical psilocybin research has prohibited concomittant SSRI use.

OBJECTIVES

We aimed to explore potential interactions between psilocybin and SSRIs by characterizing peoples' real-world experiences using psilocybin mushrooms and SSRIs together.

METHODS

We conducted a systematic search of Reddit for posts describing psilocybin mushroom and SSRI coadministration. We identified 443 eligible posts and applied qualitative content analysis to each.

RESULTS

8% of posts reported negative physical or psychological effects resulting from coadministration. These included 13 reports that may reflect serotonin toxicity, and 1 concerning for a psychotic/manic episode. 54% of posts described reduced intensity of the acute psilocybin experience, but 39% reported unchanged intensity with SSRI coadministration.

CONCLUSIONS

Psilocybin's interactions with SSRIs are likely complex and may depend on multiple factors. Prospective studies are needed to evaluate whether psilocybin treatments are reliably safe and effective in the setting of SSRI use.

The Tolerability and Safety of Psilocybin in Psychiatric and Substance-Dependence Conditions: A Systematic Review

OBJECTIVE

The objective of this systematic review is to determine the tolerability and safety of psilocybin in a variety of psychiatric and substance-dependence conditions.

DATA SOURCES

A systematic review was conducted using Embase, PubMed, Cochrane Central, and Web of Science through September 2023 using the following terminology: "psilocybin" AND "mental-disease" OR "substance-dependence" AND "disease-therapy," in addition to other synonymous key words.

STUDY SELECTION AND DATA EXTRACTION

Literature reporting acute effects and safety data following the use of psilocybin as the pharmacologic intervention in a clinical trial in adult patients with a psychiatric or substance-dependence condition were included. Following the application of inclusion and exclusion criteria, 16 studies were ultimately included in this review.

DATA SYNTHESIS

The most common treatment-emergent adverse effects reported were transient nausea and headache. Transient anxiety was reported as a frequent psychiatric effect, and 3 participants received a benzodiazepine for refractory anxiety during the psilocybin session. Psilocybin demonstrated modest increases in blood pressure and heart rate, and 1 participant received an antihypertensive for sustained hypertension during the psilocybin session. No cases of psilocybin-induced psychosis or Hallucinogen Persisting Perception Disorder were reported.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Treatment resistance remains a concern for psychiatric patients and novel therapies are needed to help alleviate the burden of morbidity and mortality. Psilocybin demonstrates promising acute and long-term safety that may allow for its use in psychiatric or substance-dependence conditions as an alternative to standards of care or in treatment-resistant patients.

CONCLUSIONS

Psilocybin has demonstrated tolerability and safety in recent literature that has investigated its therapeutic potential in a variety of psychiatric or substance-dependence conditions.

Do classic psychedelics increase the risk of seizures? A scoping review

Seizures are a concerning adverse event frequently associated with the use of psychedelics, and hence, studies involving these substances tend to exclude patients with past history of epilepsy. This is especially relevant because epileptic seizures are markedly increased in the population suffering from mental disorders, and psychedelic assisted therapy is being researched as a promising treatment for several of them. To determine the extent of the current literature on the relationship between classic psychedelics and seizures, a scoping review was performed using the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews). The search was conducted in PubMed, Web of Science, Google scholar, LILACS and Scielo, and both animal and human models were included. A total of 16 publications on humans, and 11 on animals, were found. The results are heterogeneous, but globally suggest that psychedelics may not increase the risk of seizures in healthy individuals or animals in the absence of other drugs. However, concomitant use of other substances or drugs, such as kambo or lithium, could increase the risk of seizures. Additionally, these conclusions are drawn from data lacking sufficient external validity, so they should be interpreted with caution. Future paths for research and a summary on possible neurobiological underpinnings that might clarify the relationship between classical psychedelics and seizures are also provided.

Tripping into the unknown: Exploring the experiences of first-time LSD users through global drug survey insights

BACKGROUND

The recreational use of LSD, a synthetic psychedelic drug, has surged in recent years, coinciding with a renewed research focus on its potential psychotherapeutic properties.

AIM

This study aims to describe the experiences and perceptions of individuals engaging in LSD use for the first time, derived from a large international sample.

METHODS

This study utilised 2018 Global Drug Survey data collected from 6 November 2017 to 10 January 2018. Participants who initiated LSD use in the preceding 12 months answered questions on their experiences, social settings, harm-reduction behaviours, and demographics. Descriptive statistics were employed, and characteristics of those seeking emergency medical treatment (EMT) and those not planning further LSD use were compared with other respondents.

RESULTS

Among 3340 respondents who used LSD in the past year, their first-time experiences generally exceeded expectations, with 97.7% expressing excitement. Adverse and unwanted side effects were rarely reported, and only 17 individuals needed EMT. Feelings of fear were reported by most (64.1%), but only very mildly and not enough to put them off from wanting to use LSD again.

DISCUSSION

Although the occurrence of unwanted side effects seems low and the LSD experience is generally pleasurable, vigilance amid the rising illicit use of LSD through harm-reduction education is still important in preventing possible risks.

Psilocybin desynchronizes the human brain

A single dose of psilocybin, a psychedelic that acutely causes distortions of space-time perception and ego dissolution, produces rapid and persistent therapeutic effects in human clinical trials1-4. In animal models, psilocybin induces neuroplasticity in cortex and hippocampus5-8. It remains unclear how human brain network changes relate to subjective and lasting effects of psychedelics. Here we tracked individual-specific brain changes with longitudinal precision functional mapping (roughly 18 magnetic resonance imaging visits per participant). Healthy adults were tracked before, during and for 3 weeks after high-dose psilocybin (25 mg) and methylphenidate (40 mg), and brought back for an additional psilocybin dose 6-12 months later. Psilocybin massively disrupted functional connectivity (FC) in cortex and subcortex, acutely causing more than threefold greater change than methylphenidate. These FC changes were driven by brain desynchronization across spatial scales (areal, global), which dissolved network distinctions by reducing correlations within and anticorrelations between networks. Psilocybin-driven FC changes were strongest in the default mode network, which is connected to the anterior hippocampus and is thought to create our sense of space, time and self. Individual differences in FC changes were strongly linked to the subjective psychedelic experience. Performing a perceptual task reduced psilocybin-driven FC changes. Psilocybin caused persistent decrease in FC between the anterior hippocampus and default mode network, lasting for weeks. Persistent reduction of hippocampal-default mode network connectivity may represent a neuroanatomical and mechanistic correlate of the proplasticity and therapeutic effects of psychedelics.

Psychedelic-assisted psychotherapy: where is the psychotherapy research?

RATIONALE

Psychedelic-assisted psychotherapy (PAP) has emerged as a potential treatment for a variety of mental health conditions, including substance use disorders and depression. Current models of PAP emphasize the importance of psychotherapeutic support before, during, and after ingestion of a psychedelic to maximize safety and clinical benefit. Despite this ubiquitous assumption, there has been surprisingly little empirical investigation of the "psychotherapy" in PAP, leaving critical questions about the necessary and sufficient components of PAP unanswered.

OBJECTIVES

As clinical trials for psychedelic compounds continue the transition from safety- and feasibility-testing to evaluating efficacy, the role of the accompanying psychotherapy must be better understood to enhance scientific understanding of the mechanisms underlying therapeutic change, optimize clinical outcomes, and inform cost-effectiveness.

RESULTS

The present paper first reviews the current status of psychotherapy in the PAP literature, starting with recent debates regarding "psychotherapy" versus "psychological support" and then overviewing published clinical trial psychotherapy models and putative models informed by theory. We then delineate lessons that PAP researchers can leverage from traditional psychotherapy research regarding standardizing treatments (e.g., publish treatment manuals, establish eligibility criteria for providers), identifying mechanisms of change (e.g., measure established mechanisms in psychotherapy), and optimizing clinical trial designs (e.g., consider dismantling studies, comparative efficacy trials, and cross-lagged panel designs). Throughout this review, the need for increased research into the psychotherapeutic components of treatment in PAP is underscored.

CONCLUSIONS

PAP is a distinct, integrative, and transdisciplinary intervention. Future research designs should consider transdisciplinary research methodologies to identify best practices and inform federal guidelines for PAP administration.

Current Perspectives on the Clinical Research and Medicalization of Psychedelic Drugs for Addiction Treatments: Safety, Efficacy, Limitations and Challenges

Mental health disorders and substance use disorders (SUDs) in particular, contribute greatly to the global burden of disease. Psychedelics, including entactogens and dissociative substances, are currently being explored for the treatment of SUDs, yet with less empirical clinical evidence than for other mental health disorders, such as depression or post-traumatic stress disorder (PTSD). In this narrative review, we discuss the current clinical research evidence, therapeutic potential and safety of psilocybin, lysergic acid diethylamide (LSD), ketamine, 3,4-methylenedioxymethamphetamine (MDMA) and ibogaine, particularly in the context of the SUD treatment. Our aim was to provide a balanced overview of the current research and findings on potential benefits and harms of psychedelics in clinical settings for SUD treatment. We highlight the need for more clinical research in this particular treatment area and point out some limitations and challenges to be addressed in future research.

Engaging Mood Brain Circuits with Psilocybin (EMBRACE): a study protocol for a randomized, placebo-controlled and delayed-start, neuroimaging trial in depression

BACKGROUND

Major depressive disorder (MDD) is a leading cause of disability worldwide across domains of health and cognition, affecting overall quality of life. Approximately one third of individuals with depression do not fully respond to treatments (e.g., conventional antidepressants, psychotherapy) and alternative strategies are needed. Recent early phase trials suggest psilocybin may be a safe and efficacious intervention with rapid-acting antidepressant properties. Psilocybin is thought to exert therapeutic benefits by altering brain network connectivity and inducing neuroplastic changes that endure for weeks post-treatment. Although early clinical results are encouraging, psilocybin's acute neurobiological effects on neuroplasticity have not been fully investigated. We aim to examine for the first time how psilocybin acutely (intraday) and subacutely (weeks) alters functional brain networks implicated in depression.

METHODS

Fifty participants diagnosed with MDD or persistent depressive disorder (PDD) will be recruited from a tertiary mood disorders clinic and undergo 1:1 randomization into either an experimental or control arm. Participants will be given either 25 mg psilocybin or 25 mg microcrystalline cellulose (MCC) placebo for the first treatment. Three weeks later, those in the control arm will transition to receiving 25 mg psilocybin. We will investigate whether treatments are associated with changes in arterial spin labelling and blood oxygenation level-dependent contrast neuroimaging assessments at acute and subacute timepoints. Primary outcomes include testing whether psilocybin demonstrates acute changes in (1) cerebral blood flow and (2) functional brain activity in networks associated with mood regulation and depression when compared to placebo, along with changes in MADRS score over time compared to placebo. Secondary outcomes include changes across complementary clinical psychiatric, cognitive, and functional scales from baseline to final follow-up. Serum peripheral neurotrophic and inflammatory biomarkers will be collected at baseline and follow-up to examine relationships with clinical response, and neuroimaging measures.

DISCUSSION

This study will investigate the acute and additive subacute neuroplastic effects of psilocybin on brain networks affected by depression using advanced serial neuroimaging methods. Results will improve our understanding of psilocybin's antidepressant mechanisms versus placebo response and whether biological measures of brain function can provide early predictors of treatment response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT06072898. Registered on 6 October 2023.

A rapid narrative review of the clinical evolution of psychedelic treatment in clinical trials

Pre-prohibition psychedelic research with complex psychiatric patients generated a wealth of treatment methodologies and practices, providing invaluable clinical insights pertaining to the medical administration of psychedelics in various mental health diagnoses. Building upon these early studies, which lack the rigor and research tools available today, contemporary psychedelic research has focused on investigating the safety and efficacy of psychedelics in randomized controlled trials via psychometric measures and symptom assessments. Both then and now, the treatment context and the role of clinicians in psychedelic treatment has been recognized as an essential feature for positive patient outcomes. To broaden the knowledge base of modern psychedelic research and support the training of clinicians conducting medically supervised psychedelic research studies, this paper provides a review of pre-prohibition clinical research narratives pertaining to the phenomenology of psychedelic treatment and the role of the non-pharmacological treatment factors in the patient experience. Lastly, this paper explores a range of clinician perspectives and psychological interventions employed in pre-prohibition psychedelic research to inform future research directions and best practice guidelines.

Neural Mechanisms of Resting-State Networks and the Amygdala Underlying the Cognitive and Emotional Effects of Psilocybin

BACKGROUND

Serotonergic psychedelics, such as psilocybin, alter perceptual and cognitive systems that are functionally integrated with the amygdala. These changes can alter cognition and emotions that are hypothesized to contribute to their therapeutic utility. However, the neural mechanisms of cognitive and subcortical systems altered by psychedelics are not well understood.

METHODS

We used resting-state functional magnetic resonance images collected during a randomized, double-blind, placebo-controlled clinical trial of 24 healthy adults under 0.2 mg/kg psilocybin to estimate the directed (i.e., effective) changes between the amygdala and 3 large-scale resting-state networks involved in cognition. These networks are the default mode network, the salience network, and the central executive network.

RESULTS

We found a pattern of decreased top-down effective connectivity from these resting-state networks to the amygdala. Effective connectivity decreased within the default mode network and salience network but increased within the central executive network. These changes in effective connectivity were statistically associated with behavioral measures of altered cognition and emotion under the influence of psilocybin.

CONCLUSIONS

Our findings suggest that temporary amygdala signal attenuation is associated with mechanistic changes to resting-state network connectivity. These changes are significant for altered cognition and perception and suggest targets for research investigating the efficacy of psychedelic therapy for internalizing psychiatric disorders. More broadly, our study suggests the value of quantifying the brain's hierarchical organization using effective connectivity to identify important mechanisms for basic cognitive function and how they are integrated to give rise to subjective experiences.

Development of the Japanese version of the Challenging Experience Questionnaire

INTRODUCTION

The therapeutic potential of psychedelics for various mental disorders has gained significant interest. Previous studies have highlighted that psychedelics induce psychoactive effects, including challenging aspects of experiences. These experiences are assessed using the Challenging Experience Questionnaire (CEQ), yet its Japanese version has been unavailable. This study aimed to create a Japanese version of the CEQ.

METHODS

We followed the "Principles of Good Practice for the Translation and Cultural Adaptation Process for Patient-Reported Outcomes (PRO) Measures: Report of the ISPOR Task Force for Translation and Cultural Adaptation." Initially, two Japanese psychiatrists independently conducted the forward translations. These were then reconciled into a single version, which was back-translated into English. The original authors reviewed this back-translation for accuracy, leading to revisions through continuous dialogue until the original authors approved the final version.

RESULTS

The final, approved back-translated version of the CEQ is presented in the figure.

CONCLUSIONS

This study developed a Japanese version of the CEQ, enabling the assessment of challenging experiences during psychedelic-assisted therapy for Japanese speakers. Further studies are needed to assess the reliability and validity of this newly translated version.

Psychedelics and disorders of consciousness: the current landscape and the path forward

Modern medicine has been shaken by the surge of psychedelic science that proposes a new approach to mitigate mental disorders, such as depression and post-traumatic stress disorder. Clinical trials to investigate whether psychedelic substances can treat psychiatric conditions are now underway, yet less discussion gravitates around their use in neurological disorders due to brain injury. One suggested implementation of brain-complexity enhancing psychedelics is to treat people with post-comatose disorders of consciousness (DoC). In this article, we discuss the rationale of this endeavour, examining possible outcomes of such experiments by postulating the existence of an optimal level of complexity. We consider the possible counterintuitive effects of both psychedelics and DoC on the functional connectivity of the default mode network and its possible impact on selfhood. We also elaborate on the role of computational modelling in providing complementary information to experimental studies, both contributing to our understanding of the treatment mechanisms and providing a path towards personalized medicine. Finally, we update the discourse surrounding the ethical considerations, encompassing clinical and scientific values.

Adolescent Psychedelic Use and Psychotic or Manic Symptoms

Importance

While psychedelic-assisted therapy has shown promise in the treatment of certain psychiatric disorders, little is known about the potential risk of psychotic or manic symptoms following naturalistic psychedelic use, especially among adolescents.

Objective

To investigate associations between naturalistic psychedelic use and self-reported psychotic or manic symptoms in adolescents using a genetically informative design.

Design, Setting, and Participants

This study included a large sample of adolescent twins (assessed at age 15, 18, and 24 years) born between July 1992 and December 2005 from the Swedish Twin Registry and cross-sectionally evaluated the associations between past psychedelic use and psychotic or manic symptoms at age 15 years. Individuals were included if they answered questions related to past use of psychedelics. Data were analyzed from October 2022 to November 2023.

Main Outcomes and Measures

Primary outcome measures were self-reported psychotic and manic symptoms at age 15 years. Lifetime use of psychedelics and other drugs was also assessed at the same time point.

Results

Among the 16 255 participants included in the analyses, 8889 were female and 7366 were male. Among them, 541 participants reported past use of psychedelics, most of whom (535 of 541 [99%]) also reported past use of other drugs (ie, cannabis, stimulants, sedatives, opioids, inhalants, or performance enhancers). When adjusting for substance-specific and substance-aggregated drug use, psychedelic use was associated with reduced psychotic symptoms in both linear regression analyses (β, -0.79; 95% CI, -1.18 to -0.41 and β, -0.39; 95% CI, -0.50 to -0.27, respectively) and co-twin control analyses (β, -0.89; 95% CI, -1.61 to -0.16 and β, -0.24; 95% CI, -0.48 to -0.01, respectively). In relation to manic symptoms, likewise adjusting for substance-specific and substance-aggregated drug use, statistically significant interactions were found between psychedelic use and genetic vulnerability to schizophrenia (β, 0.17; 95% CI, 0.01 to 0.32 and β, 0.17; 95% CI, 0.02 to 0.32, respectively) or bipolar I disorder (β, 0.20; 95% CI, 0.04 to 0.36 and β, 0.17; 95% CI, 0.01 to 0.33, respectively).

Conclusions and Relevance

The findings in this study suggest that, after adjusting for other drug use, naturalistic use of psychedelic may be associated with lower rates of psychotic symptoms among adolescents. At the same time, the association between psychedelic use and manic symptoms seems to be associated with genetic vulnerability to schizophrenia or bipolar I disorder. These findings should be considered in light of the study's limitations and should therefore be interpreted with caution.

[Psilocybin-Assisted Treatment of Depression, Anxiety and Substance use Disorders: Neurobiological Basis and Clinical Application]

Successful therapy of mental disorders is very important in view of the high level of suffering of those affected. Since established pharmaceutical and psychotherapeutic approaches do not lead to the desired improvement in all cases, complementary or alternative treatment methods are intensively researched. Psilocybin-assisted psychotherapy seems particularly promising, and has been approved in the USA for larger clinical trials. Psilocybin belongs to the group of psychedelics and influences psychological experiences. In assisted therapy, psilocybin is administered in controlled doses under medical supervision to patients with different mental disorders. In the studies conducted so far, longer-term positive effects could be shown after just one or a few doses. In order to provide a better understanding of the potential therapeutic mechanisms, this article will first describe neurobiological and psychological effects of psilocybin. To better assess the potential of psilocybin-assisted psychotherapy for various disorders, clinical studies conducted so far with patients administered psilocybin are reviewed.

Exploring Psychedelics for Alleviating Existential and Spiritual Suffering in People With Serious Illnesses: Links to the Theory of Self-Transcendence

The fields of palliative and holistic Nursing are dedicated to providing comprehensive care for the person, emphasizing special attention to the existential and spiritual aspects of care. Psychedelic-assisted therapy has emerged as a promising approach for symptom management in individuals with serious illnesses, particularly those of existential and spiritual origin. People who undergo challenging experiences, as is the case with serious illnesses, often undergo an identity crisis and question the purpose of their lives. Psychedelic therapy, when conducted properly by trained professionals, can facilitate self-exploration and self-transcendence, opening doors to states of expanded consciousness and fostering a profound connection with oneself. This experience can help patients develop a greater sense of self-awareness and a deeper understanding of their existential and spiritual issues, enabling them to find meaning and inner peace. The Theory of Self-Transcendence theory provides a Nursing framework for understanding how psychedelic-assisted therapy can facilitate, through self-transcendence, the journey of spiritual and existential healing, offering the possibility of achieving wellbecoming from a state of vulnerability.

Disentangling the acute subjective effects of classic psychedelics from their enduring therapeutic properties

Recent research with classic psychedelics suggests significant therapeutic potential, particularly for neuropsychiatric disorders. A mediating influence behind symptom resolution is thought to be the personal insight - at times, bordering on the mystical - one acquires during the acute phase of a psychedelic session. Indeed, current clinical trials have found strong correlations between the acute subjective effects (ASE) under the influence of psychedelics and their enduring therapeutic properties. However, with potential barriers to widespread clinical implementation, including the healthcare resource-intensive nature of psychedelic sessions and the exclusion of certain at-risk patient groups, there is an active search to determine whether ASE elimination can be accompanied by the retention of persisting therapeutic benefits of these class of compounds. Recognizing the aberrant underlying neural circuitry that characterizes a range of neuropsychiatric disorders, and that classic psychedelics promote neuroplastic changes that may correct abnormal circuitry, investigators are rushing to design and discover compounds with psychoplastogenic, but not hallucinogenic (i.e., ASE), therapeutic potential. These efforts have paved the discovery of 'non-psychedelic/subjective psychedelics', or compounds that lack hallucinogenic activity but with therapeutic efficacy in preclinical models. This review aims to distill the current evidence - both clinical and preclinical - surrounding the question: can the ASE of classic psychedelics be dissociated from their sustained therapeutic properties? Several plausible clinical scenarios are then proposed to offer clarity on and potentially answer this question.

Measuring psychotherapeutic processes in the context of psychedelic experiences: Validation of the General Change Mechanisms Questionnaire (GCMQ)

BACKGROUND

Therapeutic and salutogenic effects of psychedelic drugs have been attributed to psychotherapeutic or psychotherapy-like processes that can unfold during the acute psychedelic experience and beyond. Currently, there are no psychometric instruments available to comprehensively assess psychotherapeutic processes (as conceptualized by empirical psychotherapy research) in the context of psychedelic experiences.

AIMS

We report the initial validation of the General Change Mechanisms Questionnaire (GCMQ), a self-report instrument designed to measure five empirically established general change mechanisms (GCMs) of psychotherapy-(1) resource activation, (2) therapeutic relationship, (3) problem actuation, (4) clarification, and (5) mastery-in the context of psychedelic experiences.

METHODS

An online survey in a sample of 1153 English-speaking and 714 German-speaking psychedelic users was conducted to evaluate simultaneously developed English- and German-language versions of the GCMQ.

RESULTS

The theory-based factor structure was confirmed. The five GCMQ scales showed good internal consistency. Evidence for convergent validity with external measures was obtained. Significant associations with different settings and with therapeutic, hedonic, and escapist use motives confirmed the hypothesized context dependence of GCM-related psychedelic experiences. Indicating potential therapeutic effects, the association between cumulative stressful life events and well-being was significantly moderated by resource activation, clarification, and mastery. Factor mixture modeling revealed five distinct profiles of GCM-related psychedelic experiences.

CONCLUSION

Initial testing indicates that the GCMQ is a valid and reliable instrument that can be used in future clinical and nonclinical psychedelic research. The five identified profiles of GCM-related experiences may be relevant to clinical uses of psychedelics and psychedelic harm reduction.

Comparing Neural Correlates of Consciousness: From Psychedelics to Hypnosis and Meditation

BACKGROUND

Pharmacological and nonpharmacological methods of inducing altered states of consciousness (ASCs) are becoming increasingly relevant in the treatment of psychiatric disorders. While comparisons between them are often drawn, to date no study has directly compared their neural correlates.

METHODS

To address this knowledge gap, we directly compared 2 pharmacological methods (psilocybin 0.2 mg/kg orally [n = 23] and lysergic acid diethylamide [LSD] 100 μg orally [n = 25]) and 2 nonpharmacological methods (hypnosis [n = 30] and meditation [n = 29]) using resting-state functional connectivity magnetic resonance imaging and assessed the predictive value of the data using a machine learning approach.

RESULTS

We found that 1) no network reached significance in all 4 ASC methods; 2) pharmacological and nonpharmacological interventions of inducing ASCs showed distinct connectivity patterns that were predictive at the individual level; 3) hypnosis and meditation showed differences in functional connectivity when compared directly and also drove distinct differences when jointly compared with the pharmacological ASC interventions; and 4) psilocybin and LSD showed no differences in functional connectivity when directly compared with each other, but they did show distinct behavioral-neural relationships.

CONCLUSIONS

Overall, these results extend our understanding of the mechanisms of action of ASCs and highlight the importance of exploring how these effects can be leveraged in the treatment of psychiatric disorders.

Longitudinal associations between psychedelic use and psychotic symptoms in the United States and the United Kingdom

It has long been speculated that psychedelic use could provoke the onset of psychosis, but there is little evidence to support this conjecture. Using a longitudinal research design with samples representative of the US and UK adult populations with regard to sex, age, and ethnicity (n = 9732), we investigated associations between psychedelic use and change in the number of psychotic symptoms during the two-month study period. In covariate-adjusted regression models, psychedelic use during the study period was not associated with a change in the number of psychotic symptoms unless it interacted with a personal or family history of bipolar disorder, in which case the number of symptoms increased, or with a personal (but not family) history of psychotic disorders, in which case the number of symptoms decreased. Taken together, these findings indicate that psychedelic use may affect psychotic symptoms in individuals with a personal or family history of certain disorders characterized by psychotic symptomatology.

The psychedelic call: analysis of Australian Poisons Information Centre calls associated with classic psychedelics

INTRODUCTION

The global use of certain classical psychedelics has increased in recent years, but little is known about their spectrum of toxicity within Australia. We aim to describe calls to New South Wales Poisons Information Centre relating to exposures to classical psychedelics including lysergic acid diethylamide, psilocybin, N,N-dimethyltryptamine, ayahuasca, mescaline and ibogaine.

METHODS

This is a retrospective observational study of calls to New South Wales Poisons Information Centre between January 2014 and December 2022. We identified exposures to classical psychedelics within New South Wales Poisons Information Centre database and measured the annual number of exposures, source of call (hospital, health care worker, member of the public), co-ingested substances, clinical features and advice given.

RESULTS

There were 737 calls related to relevant psychedelic exposures; 352 (47.8 per cent) to lysergic acid diethylamide, 347 (47.0 per cent) to psilocybin, 28 (3.8 per cent) to N,N-dimethyltryptamine, 4 (0.5 per cent) to ayahuasca, 4 (0.5 per cent) to mescaline and 2 (0.3 per cent) to ibogaine. Cases were predominantly male (77.2 per cent) and aged between 20 and 74 years (65.6 per cent). Psychedelic calls more than doubled from 45 in 2014 to 105 in 2022 and 625 (85 per cent) of all calls were either from or referred to hospital. Co-ingestion of psychedelics with another substance occurred in 249 (33.8 per cent) of calls and the most frequent clinical features related to single substance psychedelic exposures were hallucinations (27.6 per cent), gastrointestinal symptoms (21.7 per cent) and tachycardia (18.1 per cent). Seizures occurred in 2.9 per cent of single substance psychedelic exposures.

DISCUSSION

Increasing incidence of psychedelic exposure calls, including those reporting significant toxicity, likely reflects increasing community use. This may in part be driven by increasing interest in psychedelic assisted psychotherapy trials subsequently increasing public awareness.

CONCLUSION

Relatively high poisoning severity contrasts with safety within clinical trials of psychedelic assisted psychotherapy that may relate to the uncontrolled nature of community use which is mitigated within clinical trial environments. Education about safe use may be useful.

Strong Bipartisan Support for Controlled Psilocybin Use as Treatment or Enhancement in a Representative Sample of US Americans: Need for Caution in Public Policy Persists

The psychedelic psilocybin has shown promise both as treatment for psychiatric conditions and as a means of improving well-being in healthy individuals. In some jurisdictions (e.g., Oregon, USA), psilocybin use for both purposes is or will soon be allowed and yet, public attitudes toward this shift are understudied. We asked a nationally representative sample of 795 US Americans to evaluate the moral status of psilocybin use in an appropriately licensed setting for either treatment of a psychiatric condition or well-being enhancement. Showing strong bipartisan support, participants rated the individual's decision as morally positive in both contexts. These results can inform effective policy-making decisions around supervised psilocybin use, given robust public attitudes as elicited in the context of an innovative regulatory model. We did not explore attitudes to psilocybin use in unsupervised or non-licensed community or social settings.

Acute Adverse Effects of Therapeutic Doses of Psilocybin: A Systematic Review and Meta-Analysis

Importance

Psilocybin has been studied in the treatment of depression and anxiety disorders. Clinical studies have mainly focused on efficacy, with systematic reviews showing favorable efficacy; however, none have primarily focused on psilocybin safety.

Objective

To evaluate the acute adverse effects of psilocybin at therapeutic doses in the treatment of depression and anxiety.

Data Sources

MEDLINE via PubMed, Web of Science, and ClinicalTrials.gov were searched for publications available between 1966 and November 30, 2023.

Study Selection

Randomized, double-blind clinical trials that reported adverse effects of psilocybin in patients treated for depression and anxiety were screened.

Data Extraction and Synthesis

Data were independently extracted by 2 authors and verified by 2 additional authors following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The inverse variance method with the Hartung-Knapp adjustment for the random-effects model was used, with a continuity correction of 0.5 for studies with 0 cell frequencies. Sensitivity analysis was conducted by sequentially removing 1 study at a time to assess the robustness of the results.

Main Outcomes and Measures

The primary outcome was considered as the adverse effects of psilocybin at high and moderate (ie, therapeutic) dose regimens and compared with placebo, low-dose psilocybin, or other comparator in the treatment of depression and/or anxiety.

Results

Six studies met the inclusion criteria with a total sample of 528 participants (approximately 51% female; median age 39.8 years; IQR, 39.8-41.2). Seven adverse effects were reported in multiple studies and included in the analysis. Among these, headache (relative risk [RR], 1.99; 95% CI 1.06-3.74), nausea (RR, 8.85; 95% CI, 5.68-13.79), anxiety (RR, 2.27; 95% CI, 1.11-4.64), dizziness (RR, 5.81; 95% CI, 1.02-33.03), and elevated blood pressure (RR, 2.29; 95% CI, 1.15- 4.53) were statistically significant. Psilocybin use was not associated with risk of paranoia and transient thought disorder.

Conclusions and Relevance

In this meta-analysis, the acute adverse effect profile of therapeutic single-dose psilocybin appeared to be tolerable and resolved within 48 hours. However, future studies need to more actively evaluate the appropriate management of adverse effects.

Psilocybin-assisted group therapy in patients with cancer diagnosed with a major depressive disorder

BACKGROUND

Depression is common in patients with cancer and is associated with lower treatment adherence and reduced quality of life. Antidepressants and psychotherapy have limited success in improving depression among patients with cancer. This study explored the safety, feasibility, and efficacy of psilocybin-assisted therapy in patients with cancer and major depressive disorder.

METHODS

This phase 2, open-label trial enrolled patients with curable and noncurable cancer and major depressive disorder at a single community oncology practice site. A single 25-mg dose of psilocybin was administered simultaneously to cohorts of three to four participants with individual (4.25 hours in 1:1 therapist-to-patient ratio) and group therapeutic support (3.75 hours) before, during, and after psilocybin administration. Outcomes included depression severity, anxiety, pain, demoralization, and disability.

RESULTS

Thirty participants completed the study. No psilocybin-related serious adverse events occurred; treatment-related adverse events (e.g., nausea, headache) were generally mild and expected. There were no laboratory or electrocardiogram abnormalities. No suicidality was reported. Efficacy was suggested with a robust reduction in depression severity scores from baseline to posttreatment of 19.1 points (95% CI, 22.3 to -16.0; p < .0001) by week 8. Eighty percent of participants demonstrated a sustained response to psilocybin treatment; 50% showed full remission of depressive symptoms at week 1, which was sustained for 8 weeks.

CONCLUSIONS

Psilocybin-assisted therapy in group cohort administration was safe and feasible in patients with cancer and depression. Efficacy was suggested based on clinically meaningful reductions in depressive symptoms. The novel, group-oriented format, compact delivery time, community cancer center setting, and one-to-one therapist-to-patient ratio could also add to therapeutic gains and efficiency of administration.

TRIAL REGISTRATION

NCT04593563.

PLAIN LANGUAGE SUMMARY

Depression is common in patients with cancer and associated with lower treatment adherence, reduced quality of life, and limited response to antidepressants and psychotherapy. We conducted a phase 2 trial to study a single dose of psilocybin administered in a group therapy setting with one-to-one therapist-to-participant psychological support to patients with curable and noncurable cancer and major depressive disorder. Findings of the study showed safety (no treatment-related serious adverse events or suicidality) with psilocybin and suggested efficacy, with a significant reduction in depression severity scores from baseline to posttreatment. Further investigation is warranted.

Deep CANALs: a deep learning approach to refining the canalization theory of psychopathology

Psychedelic therapy has seen a resurgence of interest in the last decade, with promising clinical outcomes for the treatment of a variety of psychopathologies. In response to this success, several theoretical models have been proposed to account for the positive therapeutic effects of psychedelics. One of the more prominent models is "RElaxed Beliefs Under pSychedelics," which proposes that psychedelics act therapeutically by relaxing the strength of maladaptive high-level beliefs encoded in the brain. The more recent "CANAL" model of psychopathology builds on the explanatory framework of RElaxed Beliefs Under pSychedelics by proposing that canalization (the development of overly rigid belief landscapes) may be a primary factor in psychopathology. Here, we make use of learning theory in deep neural networks to develop a series of refinements to the original CANAL model. Our primary theoretical contribution is to disambiguate two separate optimization landscapes underlying belief representation in the brain and describe the unique pathologies which can arise from the canalization of each. Along each dimension, we identify pathologies of either too much or too little canalization, implying that the construct of canalization does not have a simple linear correlation with the presentation of psychopathology. In this expanded paradigm, we demonstrate the ability to make novel predictions regarding what aspects of psychopathology may be amenable to psychedelic therapy, as well as what forms of psychedelic therapy may ultimately be most beneficial for a given individual.

Ethical considerations for psychedelic-assisted therapy in military clinical settings

Psychedelic treatments, particularly 3,4-methylenedioxymethamphetamine (MDMA)-assisted and psilocybin-assisted therapies, have recently seen renewed interest in their clinical potential to treat various mental health conditions. Clinical trials for both MDMA-assisted and psilocybin-assisted therapies have shown to be highly efficacious for post-traumatic stress disorder and major depression. Recent research trials for psychedelic-assisted therapies (PAT) have demonstrated that although they are resource-intensive, their effects are rapid-acting, durable and cost-effective. These results have generated enthusiasm among researchers seeking to investigate psychedelic therapies in active-duty service members of the US military, particularly those with treatment refractory mental health conditions. At the same time, psychedelics remain in early stages of clinical investigation, have not yet achieved regulatory approval for general clinical use and may confer unique psychological and neurobiological effects that could raise novel ethical considerations when treating active-duty service members. Should psychedelics achieve regulatory approval, military relevant considerations may include issues of access to these treatments, appropriate procedures for informed consent, confidentiality standards, and possible unanticipated mental health risks and other psychological sequelae. A service member's deployability, as well as their ability to return to full military duty following PAT, may also be of unique concern. The authors argue that MDMA-assisted therapy currently represents a promising treatment that should be more rapidly investigated as a clinical therapy for service members while still taking a measured approach that accounts for the many military-specific uncertainties that remain.

The therapeutic alliance between study participants and intervention facilitators is associated with acute effects and clinical outcomes in a psilocybin-assisted therapy trial for major depressive disorder

We examined if the therapeutic alliance between study participants and intervention facilitators in a psilocybin-assisted therapy (PAT) trial changed over time and whether there were relationships between alliance, acute psilocybin experiences, and depression outcomes. In a randomized, waiting list-controlled clinical trial for major depressive disorder in adults (N = 24), participants were randomized to an immediate (N = 13) or delayed (N = 11) condition with two oral doses of psilocybin (20mg/70kg and 30mg/70kg). Ratings of therapeutic alliance significantly increased from the final preparation session to one-week post-intervention (p = .03, d = .43). A stronger total alliance at the final preparation session predicted depression scores at 4 weeks (r = -.65, p = .002), 6 months (r = -.47, p = .036), and 12 months (r = -.54, p = .014) post-intervention. A stronger total alliance in the final preparation session was correlated with higher peak ratings of mystical experiences (r = .49, p = .027) and psychological insight (r = .52, p = .040), and peak ratings of mystical experience and psychological insight were correlated with depression scores at 4 weeks (r = -.45, p = .030 for mystical; r = -.75, p < .001 for insight). Stronger total alliance one week after the final psilocybin session predicted depression scores at 4 weeks (r = -.85, p < .001), 3 months (r = -.52, p = .010), 6 months (r = -.77, p < .001), and 12 months (r = -.61, p = .001) post-intervention. These findings highlight the importance of the therapeutic relationship in PAT. Future research should explore therapist and participant characteristics which maximize the therapeutic alliance and evaluate its relationship to treatment outcomes. Trial registration: Registration: Clinicaltrials.gov NCT03181529. https://classic.clinicaltrials.gov/ct2/show/NCT03181529.

Psilocybin-assisted psychotherapy for treatment resistant depression: A randomized clinical trial evaluating repeated doses of psilocybin

BACKGROUND

Psilocybin-assisted psychotherapy (PAP) has been associated with antidepressant effects. Trials to date have typically excluded participants with complex presentations. Our aim was to determine the feasibility of PAP in a complex population, including high levels of treatment resistance in major depressive and bipolar disorder and patients with baseline suicidality and significant comorbidity. We also evaluated flexible repeated doses over a 6-month period.

METHODS

Adults with treatment-resistant depression as part of major depressive or bipolar II disorder without psychosis or a substance use disorder were eligible to participate. Subjects were randomized to immediate treatment or waitlist control, with all eventually receiving PAP. Participants had one, two, or three psilocybin sessions with a fixed dose of 25 mg. Each dose was accompanied by preparation and integration psychotherapy sessions. Acceptability, safety, tolerability, and efficacy were evaluated (this study was registered at ClinicalTrials.gov: NCT05029466).

FINDINGS

Participants were randomized to immediate treatment (n = 16) or delayed treatment (n = 14). 29/30 were retained to the week-2 primary endpoint. Adverse events were transient, with no serious adverse events. Greater reductions in depression severity as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS) were observed in the immediate treatment arm compared to the waitlist period arm with a large hedge's g effect size of 1.07 (p < 0.01). Repeated doses were associated with further reductions in MADRS scores compared to baseline.

CONCLUSIONS

PAP was feasible in complex patients with preliminary antidepressant efficacy and adequate safety and tolerability. Repeated doses were associated with greater reductions in depression severity.

FUNDING

This work was funded by Brain and Cognition Discovery Foundation (BCDF), Usona, and Braxia Scientific.

Antidepressant-like effects of psychedelics in a chronic despair mouse model: is the 5-HT2A receptor the unique player?

Major depressive disorder (MDD) is one of the most disabling psychiatric disorders in the world. First-line treatments such as selective serotonin reuptake inhibitors (SSRIs) still have many limitations, including a resistance to treatment in 30% of patients and a delayed clinical benefit that is observed only after several weeks of treatment. Increasing clinical evidence indicates that the acute administration of psychedelic agonists of the serotonin 5-HT2A receptor (5-HT2AR), such as psilocybin, to patients with MDD induce fast antidepressant effects, which persist up to five weeks after the treatment. However, the involvement of the 5-HT2AR in these antidepressant effects remains controversial. Furthermore, whether the hallucinogenic properties of 5-HT2AR agonists are mandatory to their antidepressant activity is still an open question. Here, we addressed these issues by investigating the effect of two psychedelics of different chemical families, DOI and psilocybin, and a non-hallucinogenic 5-HT2AR agonist, lisuride, in a chronic despair mouse model exhibiting a robust depressive-like phenotype. We show that a single injection of each drug to wild type mice induces anxiolytic- and antidepressant-like effects in the novelty-suppressed feeding, sucrose preference and forced swim tests, which last up to 15 days. DOI and lisuride administration did not produce antidepressant-like effects in 5-HT2A-/- mice, whereas psilocybin was still effective. Moreover, neither 5-HT1AR blockade nor dopamine D1 or D2 receptor blockade affected the antidepressant-like effects of psilocybin in 5-HT2A-/- mice. Collectively, these findings indicate that 5-HT2AR agonists can produce antidepressant-like effects independently of hallucinogenic properties through mechanisms involving or not involving the receptor.

Psychedelic Therapy: A Primer for Primary Care Clinicians-N,N-Dimethyltryptamine and Ayahuasca

BACKGROUND

N,N-dimethyltryptamine (DMT) is a naturally occurring serotonergic psychedelic found in natural plants around the globe. As the main psychoactive component in ayahuasca, which also contains monoamine oxidase inhibitors, DMT has been consumed as plant-based brew by indigenous peoples for centuries. Further research is required to delineate the therapeutic utility of DMT.

AREAS OF UNCERTAINTY

Although previous research has shown that DMT is synthesized endogenously, it may not be produced at physiologically relevant concentrations. Additionally, the phenomenological similarities between the DMT-induced state and near-death experiences led to the popular hypothesis that endogenous DMT is released during the dying process. However, this hypothesis continues to be debated. Generally, DMT and ayahuasca seem to be physiologically and psychiatrically safe, although ayahuasca is known to cause transient vomiting.

THERAPEUTIC ADVANCES

A double-blind, randomized controlled trial showed that, within 1 week, ayahuasca causes remission in 36% of patients with treatment-resistant depression. According to top-line results from a recent phase IIa trial, 57% of patients with major depressive disorder experienced remission 12 weeks after receiving a single intravenous dose of DMT.

LIMITATIONS

There has only been a single published double-blind randomized controlled trial on ayahuasca and 2 on DMT. All clinical trials have had small sample sizes (≤34 participants). DMT requires further research to understand its therapeutic and clinical potential as a psychedelic.

CONCLUSIONS

Preliminary evidence indicates that ayahuasca and DMT may be more effective than existing antidepressants for treating major depressive disorder and treatment-resistant depression.

Safety and tolerability of inhaled N,N-Dimethyltryptamine (BMND01 candidate): A phase I clinical trial

Psychedelics are being increasingly examined for their therapeutic potential in mood disorders. While the acute effects of ayahuasca, psilocybin, and lysergic acid diethylamide (LSD) last over several hours, inhaled N,N-Dimethyltryptamine (DMT) effects last around 10 min, which might provide a cost- and time-effective alternative to the clinical application of oral psychedelics. We aimed at investigating the safety and tolerability of inhaled DMT (BMND01 candidate). We recruited 27 healthy volunteers to receive a first, lower dose and a second, higher dose (5/20 mg, 7.5/30 mg, 10/40 mg, 12.5/50 mg, or 15/60 mg) of inhaled DMT in an open-label, single-ascending, fixed-order, dose-response study design. We investigated subjective experiences (intensity, valence, and phenomenology), physiological effects (blood pressure, heart rate, respiratory rate, blood oxygen saturation, body temperature), biochemical markers (liver, kidney, and metabolic functions), and adverse events during the acute and post-acute effects of DMT. DMT dose-dependently increased intensity, valence and perceptual ratings. There was a mild, transient, and self-limited increase in blood pressure and heart rate. There were no changes in safety blood biomarkers and no serious adverse events. DMT dose-dependently enhanced subjective experiences and positive valence. Inhaled DMT might be an efficient, non-invasive, safe route of administration, which might simplify the clinical use of this substance. This is the first clinical trial to test the effects of inhaled DMT (BMND01 candidate).

Psychiatric risks for worsened mental health after psychedelic use

BACKGROUND

Resurgent psychedelic research has largely supported the safety and efficacy of psychedelic therapy for the treatment of various psychiatric disorders. As psychedelic use and therapy increase in prevalence, so does the importance of understanding associated risks. Cases of prolonged negative psychological responses to psychedelic therapy seem to be rare; however, studies are limited by biases and small sample sizes. The current analytical approach was motivated by the question of whether rare but significant adverse effects have been under-sampled in psychedelic research studies.

METHODS

A "bottom margin analysis" approach was taken to focus on negative responders to psychedelic use in a pool of naturalistic, observational prospective studies (N = 807). We define "negative response" by a clinically meaningful decline in a generic index of mental health, that is, one standard error from the mean decrease in psychological well-being 4 weeks post-psychedelic use (vs pre-use baseline). We then assessed whether a history of diagnosed mental illness can predict negative responses.

RESULTS

We find that 16% of the cohort falls into the "negative responder" subset. Parsing the sample by self-reported history of psychiatric diagnoses, results revealed a disproportionate prevalence of negative responses among those reporting a prior personality disorder diagnosis (31%). One multivariate regression model indicated a greater than four-fold elevated risk of adverse psychological responses to psychedelics in the personality disorder subsample (b = 1.425, p < 0.05).

CONCLUSION

We infer that the presence of a personality disorder may represent an elevated risk for psychedelic use and hypothesize that the importance of psychological support and good therapeutic alliance may be increased in this population.

Psychedelic substitution: altered substance use patterns following psychedelic use in a global survey

Introduction

Recent research suggests that psychedelics may have potential for the treatment of various substance use disorders. However, most studies to date have been limited by small sample sizes and neglecting to include non-North American and European populations.

Methods

We conducted a global, cross-sectional online survey of adults (n = 5,268, 47.2% women) self-reporting past or current psychedelic use and investigated whether psychedelic use was associated with changes in use of other substances.

Results

Nearly three-quarters (70.9%; n = 3,737/5,268) reported ceasing or decreasing use of one or more non-psychedelic substances after naturalistic psychedelic use. Among those with previous use, 60.6% (n = 2,634/4,344) decreased alcohol use, 55.7% (n = 1,223/2,197) decreased antidepressant use, and 54.2% (n = 767/1,415) decreased use of cocaine/crack. Over a quarter of the sample indicated that their decrease in substance use persisted for 26 weeks or more following use of a psychedelic. Factors associated with decreased use included a motivation to either decrease one's substance use or self-treat a medical condition. Importantly, 19.8% of respondents also reported increased or initiated use of one or more other substances after psychedelic use, with illicit opioids (14.7%; n = 86/584) and cannabis (13.3%; n = 540/4,064) having the highest proportions. Factors associated with increased substance use included having a higher income and residing in Canada or the US.

Discussion

Although limited by cross-sectional study design, this large observational study will help inform future studies aiming to investigate the relationship between substance use patterns and psychedelic use.

Giving Consent to the Ineffable

A psychedelic renaissance is currently taking place in mental healthcare. The number of psychedelic-assisted therapy trials is growing steadily, and some countries already grant psychiatrists special permission to use psychedelics in non-research contexts under certain conditions. These clinical advances must be accompanied by ethical inquiry. One pressing ethical question involves whether patients can even give informed consent to psychedelic-assisted therapy: the treatment's transformative nature seems to block its assessment, suggesting that patients are unable to understand what undergoing psychedelic-assisted therapy actually means for them and whether it aligns with their values. The present paper argues that patients often have sufficient knowledge to give informed consent because they know that they want to change their negative status quo and that psychedelic-assisted therapy offers an effective way to do so. Accordingly, patients can understand what the transformative nature of psychedelic-assisted therapy means for them and a make a value-aligned choice even if they are unable to anticipate the manifestation of a psychedelic experience.

Perioperative considerations for patients exposed to hallucinogens

Hallucinogen exposure in patients in the perioperative period presents challenges for anesthesiologists and other anesthesia providers. Acute and chronic exposure to these substances can cause physiological impacts that can affect the function of anesthetic and analgesic medications used during perioperative care. The objective of this narrative review is to educate readers on the wide array of hallucinogens and psychedelics that may influence the perioperative management of patients exposed to these substances. A narrative review of the literature surrounding hallucinogens and psychedelics was completed. Hallucinogens and psychedelics are quite varied in their mechanisms of action and therefore present a variety of perioperative implications and perioperative considerations. Many of these substances increase serotonin levels or act directly at serotonergic receptors. However, there are other relevant actions that may include varied mechanisms from N-methyl-D-aspartate receptor antagonism to stimulation of muscarinic receptors. With hallucinogen exposure rates on the rise, understanding the effects of hallucinogens is important for optimizing management and reducing risks perioperatively for patients with acute or chronic exposure.

PAM trial protocol: a randomised feasibility study of psychedelic microdosing-assisted meaning-centred psychotherapy in advanced stage cancer patients

BACKGROUND

An advanced cancer diagnosis can be associated with a significant profile of distress. Psychedelic compounds have shown clinically significant effects in the treatment of psychological distress in patients with advanced-stage cancer. Given the challenges of delivering timely and effective intervention in the advanced cancer context, it is possible that an alternative, more pragmatic, approach lies in psychedelic 'microdosing'. Microdosing refers to repeated administration of psychedelics in sub-hallucinogenic doses. The purpose of this study is to evaluate the feasibility of conducting a full-scale randomised controlled trial comparing psychedelic microdose-assisted-meaning-centred psychotherapy (PA-MCP) to standard meaning-centred psychotherapy (MCP) in New Zealand indigenous (Māori) and non-indigenous people with advanced cancer and symptoms of anxiety and/or depression. Although MCP is a well-established psychotherapeutic treatment in advanced cancer populations, the potential efficacy and effectiveness of this therapy when delivered alongside a standardised microdose regimen of a psychedelic compound have not been investigated.

METHODS

Participants with advanced-stage cancer and symptoms of anxiety and/or depression (N = 40; 20 Māori, 20 non-Māori) will be randomised under double-blind conditions to receive 7 sessions of MCP alongside 13 doses of either an LSD microdose (4-20 µg) (PA-MCP) or inactive placebo (placebo-MCP). The feasibility, acceptability, and safety of this intervention and physiological and psychological measures will be recorded at baseline, at each session of MCP, and at a 1-month and 6-month follow-up.

DISCUSSION

Our findings will evaluate the feasibility, acceptability, and safety of a larger randomised controlled trial and provide an initial indication of the potential benefits of psychedelic microdosing for psychological distress in advanced-stage indigenous and non-indigenous cancer patients.

TRIAL REGISTRATION

NZCTR, ACTRN12623000478617. Registered 11 May 2023.  https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385810&isReview=true .

Effects of External Stimulation on Psychedelic State Neurodynamics

Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes, such as personality changes. These findings are particularly intriguing, given that a decrease of brain entropy is a robust indicator of loss of consciousness (e.g., from wakefulness to sleep). However, little is known about how context impacts the entropy-enhancing effect of psychedelics, which carries important implications for how it can be exploited in, for example, psychedelic psychotherapy. This article investigates how brain entropy is modulated by stimulus manipulation during a psychedelic experience by studying participants under the effects of lysergic acid diethylamide (LSD) or placebo, either with gross state changes (eyes closed vs open) or different stimuli (no stimulus vs music vs video). Results show that while brain entropy increases with LSD under all of the experimental conditions, it exhibits the largest changes when subjects have their eyes closed. Furthermore, brain entropy changes are consistently associated with subjective ratings of the psychedelic experience, but this relationship is disrupted when participants are viewing a video─potentially due to a "competition" between external stimuli and endogenous LSD-induced imagery. Taken together, our findings provide strong quantitative evidence of the role of context in modulating neural dynamics during a psychedelic experience, underlining the importance of performing psychedelic psychotherapy in a suitable environment.

Patient perspectives and experiences with psilocybin treatment for treatment-resistant depression: a qualitative study

Psilocybin is the most researched classic psychedelic for Treatment-Resistant Depression (TRD). While optimizing set and setting are considered essential for efficacy and safety, patient perspectives on these aspects have rarely been investigated. To address this knowledge gap, the current paper explored the experiences of 11 TRD patients (8 women, 3 men) participating in a double-blind randomized clinical trial with a single session of oral (1, 10 or 25 mg) psilocybin treatment. After qualitative analysis, three major themes were identified: (1) challenges with trust-building and expectation management; (2) navigating the experience; and (3) the need for a more comprehensive treatment. Subthemes of the first theme include a general distrust in mental healthcare, trust in study therapists, limited time for preparation, and managing expectations. The second theme included the following subthemes: trusting to surrender, profound and overwhelming experiences, and music as a guide. The third theme addressed a desire for multiple psilocybin sessions, and challenges with sensemaking. Patients' perspectives provided important insights into potential optimization of psilocybin treatment of TRD, including individualized preparation, investment in trust-building, offering additional psilocybin sessions, providing access to sustained (psycho)therapy with trusted therapists, and personalizing treatment approaches, which may also enhance real-world adaption of these treatments.