Classic Psychedelic Coadministration with Lithium, but Not Lamotrigine, is Associated with Seizures: An Analysis of Online Psychedelic Experience Reports

Psychotomimetic compensation versus sensitization

It is a paradox that psychotomimetic drugs can relieve symptoms that increase risk of and cooccur with psychosis, such as attention and motivational deficits (e.g., amphetamines), pain (e.g., cannabis) and symptoms of depression (e.g., psychedelics, dissociatives). We introduce the ideas of psychotomimetic compensation and psychotomimetic sensitization to explain this paradox. Psychotomimetic compensation refers to a short-term stressor or drug-induced compensation against stress that is facilitated by engagement of neurotransmitter/modulator systems (endocannabinoid, serotonergic, glutamatergic and dopaminergic) that mediate the effects of common psychotomimetic drugs. Psychotomimetic sensitization occurs after repeated exposure to stress and/or drugs and is evidenced by the gradual intensification and increase of psychotic-like experiences over time. Theoretical and practical implications of this model are discussed.

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.

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.

Hypertensive Emergency Secondary to Combining Psilocybin Mushrooms, Extended Release Dextroamphetamine-Amphetamine, and Tranylcypromine

Data on medication interactions with psychedelics are limited. Here we present what may be the first published report of a hypertensive emergency following the combination of psilocybin mushrooms with a monoamine oxidase inhibitor (MAOI). A 42-year-old man with treatment-resistant major depressive disorder took 1 g of Psilocybe cubensis mushrooms, while prescribed tranylcypromine, extended-release dextroamphetamine-amphetamine, and other medications. Approximately half an hour later, he developed severe hypertension with chest pain, palpitations, and headache. Upon hospital presentation, the electrocardiogram demonstrated ST-elevation. The patient was diagnosed with a myocardial infarction and treated with lorazepam, nitroglycerin, and aspirin. He subsequently underwent emergency cardiac catheterization, which revealed no significant cardiac abnormalities. Following overnight hospitalization, he was discharged home with no lasting physical sequelae. Though data are few, past studies suggest that classic serotonergic psychedelics (5HT-2A receptor agonists) such as dimethyltryptamine (DMT), lysergic acid (LSD), and synthetic psilocybin should not produce hypertensive emergency when combined with MAOIs. We suspect phenylethylamine, found in Psilocybe cubensis and other species of psilocybin mushrooms, interacted with tranylcypromine and dextroamphetamine-amphetamine to produce this hypertensive emergency. Patients prescribed MAOIs should be warned of the potential for hypertensive emergency when consuming psilocybin mushrooms, particularly when also prescribed norepinephrine releasers such as dextroamphetamine-amphetamine.

UK medical students' self-reported knowledge and harm assessment of psychedelics and their application in clinical research: a cross-sectional study

OBJECTIVE

To capture UK medical students' self-reported knowledge and harm assessment of psychedelics and to explore the factors associated with support for changing the legal status of psychedelics to facilitate further clinical research.

DESIGN

Cross-sectional, anonymous online survey of UK medical students using a non-random sampling method.

SETTING

UK medical schools recognised by the General Medical Council.

PARTICIPANTS

132 medical students who had spent an average of 3.8 years (SD=1.4; range: 1-6) in medical school.

RESULTS

Most students (83%) reported that they were aware of psychedelic research and only four participants (3%) said that they were not interested in learning more about this type of research. Although medical students' harm assessment of psychedelics closely aligned with that of experts, only 17% of students felt well-educated on psychedelic research. Teachings on psychedelics were only rarely encountered in their curriculum (psilocybin: 14.1 (SD=19.9), scale: 0 (never) to 100 (very often)). Time spent at medical schools was not associated with more knowledge about psychedelics (r=0.12, p=0.129). On average, this sample of medical students showed strong support for changing the legal status of psychedelics to facilitate further research into their potential clinical applications (psilocybin: 80.2 (SD=24.8), scale: 0 (strongly oppose) to 100 (strongly support)). Regression modelling indicated that greater knowledge of psychedelics (p<0.001), lower estimated harm scores (p<0.001), more time spent in medical school (p=0.024) and lower perceived effectiveness of non-pharmacological mental health treatments (p=0.044) were associated with greater support for legal status change.

CONCLUSIONS

Our findings reveal a significant interest among UK medical students to learn more about psychedelic research and a strong support for further psychedelic research. Future studies are needed to examine how medical education could be refined to adequately prepare medical students for a changing healthcare landscape in which psychedelic-assisted therapy could soon be implemented in clinical practice.

Drug-drug interactions involving classic psychedelics: A systematic review

Classic psychedelics, including lysergic acid diethylamide (LSD), psilocybin, mescaline, N,N-dimethyltryptamine (DMT) and 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), are potent psychoactive substances that have been studied for their physiological and psychological effects. However, our understanding of the potential interactions and outcomes when using these substances in combination with other drugs is limited. This systematic review aims to provide a comprehensive overview of the current research on drug-drug interactions between classic psychedelics and other drugs in humans. We conducted a thorough literature search using multiple databases, including PubMed, PsycINFO, Web of Science and other sources to supplement our search for relevant studies. A total of 7102 records were screened, and studies involving human data describing potential interactions (as well as the lack thereof) between classic psychedelics and other drugs were included. In total, we identified 52 studies from 36 reports published before September 2, 2023, encompassing 32 studies on LSD, 10 on psilocybin, 4 on mescaline, 3 on DMT, 2 on 5-MeO-DMT and 1 on ayahuasca. These studies provide insights into the interactions between classic psychedelics and a range of drugs, including antidepressants, antipsychotics, anxiolytics, mood stabilisers, recreational drugs and others. The findings revealed various effects when psychedelics were combined with other drugs, including both attenuated and potentiated effects, as well as instances where no changes were observed. Except for a few case reports, no serious adverse drug events were described in the included studies. An in-depth discussion of the results is presented, along with an exploration of the potential molecular pathways that underlie the observed effects.

Psychedelic renaissance: Revitalized potential therapies for psychiatric disorders

Psychiatric disorders represent the largest cause of disability worldwide. Global interests in psychedelic substances as potentially therapeutic agents for psychiatric disorders has recently re-emerged. Here, we review progress in the development of psychedelic compounds that have potential therapeutic effects as well as the safety concerns. We include psilocybin, N,N-dimethyltryptamine (DMT), lysergic acid diethylamide (LSD), and the entactogen 3,4-methyl-enedioxy-methamphetamine (MDMA). We also review the potential interactive effects these compounds can have with psychotherapeutic approaches. We provide a cutting-edge review of active and recently completed clinical trials based on the published literature (from MEDLINE), published abstracts at citable conferences, clinical trials from the US Clinical Trials registry (clinicaltrials.gov) and media press releases.

Naturalistic psilocybin use is associated with persisting improvements in mental health and wellbeing: results from a prospective, longitudinal survey

Introduction

The classic psychedelic psilocybin, found in some mushroom species, has received renewed interest in clinical research, showing potential mental health benefits in preliminary trials. Naturalistic use of psilocybin outside of research settings has increased in recent years, though data on the public health impact of such use remain limited.

Methods

This prospective, longitudinal study comprised six sequential automated web-based surveys that collected data from adults planning to take psilocybin outside clinical research: at time of consent, 2 weeks before, the day before, 1-3 days after, 2-4 weeks after, and 2-3 months after psilocybin use.

Results

A sample of 2,833 respondents completed all baseline assessments approximately 2 weeks before psilocybin use, 1,182 completed the 2-4 week post-use survey, and 657 completed the final follow-up survey 2-3 months after psilocybin use. Participants were primarily college-educated White men residing in the United States with a prior history of psychedelic use; mean age = 40 years. Participants primarily used dried psilocybin mushrooms (mean dose = 3.1 grams) for "self-exploration" purposes. Prospective longitudinal data collected before and after a planned psilocybin experience on average showed persisting reductions in anxiety, depression, and alcohol misuse, increased cognitive flexibility, emotion regulation, spiritual wellbeing, and extraversion, and reduced neuroticism and burnout after psilocybin use. However, a minority of participants (11% at 2-4 weeks and 7% at 2-3 months) reported persisting negative effects after psilocybin use (e.g., mood fluctuations, depressive symptoms).

Discussion

Results from this study, the largest prospective survey of naturalistic psilocybin use to date, support the potential for psilocybin to produce lasting improvements in mental health symptoms and general wellbeing.

Naturalistic Psychedelic Use: A World Apart from Clinical Care

Interest in and availability of psychedelics for therapeutic purposes has increased in recent decades. In a large, anonymous, online survey, we investigated patterns of communication with healthcare providers and awareness and utilization of substance testing kits or services among people using psychedelics naturalistically. The sample population included attendees of a psychedelic activism event and users of psychedelic social media forums. Among 1,435 participants, 72.5% never discussed psychedelic use with their primary care provider (PCP). Only 4.4% reported using psychedelics with a therapist and 3% in clinical settings, although 77.8% were very or extremely likely to take psychedelics with a therapist if one were legally available. While 62.6% of participants were aware of substance testing services, 42.6% of these indicated never using them. Regression analyses identified several variables associated with disclosure to PCP and utilization of substance testing services including age, gender, frequency and number of psychedelics used, and likelihood of consuming psychedelics under the guidance of a therapist if one were legally available. Further research is necessary to investigate these findings among other groups. Our findings suggest that relevant training and education for healthcare providers is needed, along with more visible options for substance identity testing.

A Qualitative Analysis of First-Hand Accounts of Diphenhydramine Misuse Available on YouTube

Deliriants are the least studied class of hallucinogens and display noticeable subjective effects, including dysphoria, hallucinations, and substantial alterations in thought. High doses of diphenhydramine (DPH), an over-the-counter antihistamine medication, can produce deliriant effects due to secondary anticholinergic activity. We sought to characterize the subjective experiences produced by DPH misuse to better understand deliriants more broadly and the context under which DPH misuse occurs. To conduct our analysis, 32 first-hand accounts of DPH misuse publicly available in YouTube videos were analyzed using inductive thematic analysis. Video makers discussed alterations in most sensory modalities, confusion, and a tendency for strongly unpleasant experiences. Occasionally, video makers reported positive effects, although these were rare and often overshadowed by negative aspects of the experience. Video makers frequently warned against misusing DPH, and these individuals occasionally reported adverse post-acute effects. Despite the prevalence of adverse experiences, patterns of repeated misuse were sometimes discussed. Motives for misusing DPH, when mentioned, included accessibility, affordability, and legality. Overall, findings suggest DPH misuse can produce substantial psychoactive effects that are often distressing and share some phenomenological overlap with experiences produced by psychosis.

Co-use of MDMA with psilocybin/LSD may buffer against challenging experiences and enhance positive experiences

Psilocybin and lysergic acid diethylamide (LSD) experiences can range from very positive to highly challenging (e.g., fear, grief, and paranoia). These challenging experiences contribute to hesitancy toward psychedelic-assisted psychotherapy among health care providers and patients. Co-use of 3,4-Methylenedioxy methamphetamine (MDMA) with psilocybin/LSD anecdotally reduces challenging experiences and enhances positive experiences associated with psilocybin/LSD. However, limited research has investigated the acute effects of co-use of MDMA and psilocybin/LSD. In a prospective convenience sample (N = 698) of individuals with plans to use psilocybin/LSD, we examined whether co-use of MDMA with psilocybin/LSD (n = 27) is associated with differences in challenging or positive experiences. Challenging experiences were measured using the Challenging Experiences Questionnaire and positive experiences were measured using the Mystical Experience Questionnaire and single-item measures of self-compassion, compassion, love, and gratitude. Potentially confounding variables were identified and included as covariates. Relative to psilocybin/LSD alone, co-use of psilocybin/LSD with a self-reported low (but not medium-high) dose of MDMA was associated with significantly less intense total challenging experiences, grief, and fear, as well as increased self-compassion, love and gratitude. Co-use of psilocybin/LSD and MDMA was not associated with differences in mystical-type experiences or compassion. Findings suggest co-use of MDMA with psilocybin/LSD may buffer against some aspects of challenging experiences and enhance certain positive experiences. Limitations include use of a convenience sample, small sample size, and non-experimental design. Additional studies (including controlled dose-response studies) that examine the effects and safety of co-administering MDMA with psilocybin/LSD (in healthy controls and clinical samples) are warranted and may assist the development of personalized treatments.

Prevalence and associations of challenging, difficult or distressing experiences using classic psychedelics

Previous studies have investigated challenging, difficult, or distressing classic psychedelic experiences, but little is known about the prevalence and associations of such experiences. Using nationally representative data of the US adult population (N = 2822), this study examined the prevalence and associations of challenging, difficult, or distressing experiences using classic psychedelics, in a subsample of respondents who reported lifetime classic psychedelic use (n = 613). Of the 613 respondents who reported lifetime classic psychedelic use, the majority of them (59.1 %) had never had a challenging, difficult, or distressing experience using a classic psychedelic, but 8.9 % of respondents reported functional impairment that lasted longer than one day as a result of such experiences. Notably, 2.6 % reported seeking medical, psychiatric, or psychological assistance in the days or weeks following their most challenging, difficult, or distressing classic psychedelic experience. In covariate-adjusted regression models, co-use of lithium, co-use of other mood stabilizers, and six set and setting variables (no preparation, disagreeable physical environment, negative mindset, no psychological support, dose was too large, major life event prior to experience) were associated with the degree of difficulty; and co-use of lithium, co-use of other mood stabilizers, and three set and setting variables (negative mindset, no psychological support, major life event prior to experience) were associated with overall risk of harm. In summary, this study provides insight into the prevalence and associations of challenging, difficult, or distressing classic psychedelic experiences. The findings broadly correspond with findings from previous studies and can inform harm reduction efforts and future experimental research designs.

Psilocybin services in Oregon: a call for awareness among clinical toxicologists

BACKGROUND

In 2023, Oregon enacted laws regulating the manufacture and use of psilocybin products in licensed facilities for supervised sessions with trained facilitators.

COMMENTARY

This commentary summarizes the final rules for psilocybin services in Oregon, and provides perspectives from a clinical toxicologist on some of the issues that may arise. These include the scope of practice for non-clinical facilitators, prevention and management of adverse drug reactions, and toxicological uncertainties with regards to dose considerations for people with mental health and other medical conditions.

CONCLUSION

This commentary addresses some common misperceptions relating to the program, and provides perspective on some of the challenges that clinical toxicologists may encounter as legislative reform initiatives for psilocybin move forward throughout the United States.

The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: Serotonergic Psychedelic Treatments for Major Depressive Disorder

OBJECTIVE

Serotonergic psychedelics are re-emerging as potential novel treatments for several psychiatric disorders including major depressive disorder. The Canadian Network for Mood and Anxiety Treatments (CANMAT) convened a task force to review the evidence and provide a consensus recommendation for the clinical use of psychedelic treatments for major depressive disorder.

METHODS

A systematic review was conducted to identify contemporary clinical trials of serotonergic psychedelics for the treatment of major depressive disorder and cancer-related depression. Studies published between January 1990 and July 2021 were identified using combinations of search terms, inspection of bibliographies and review of other psychedelic reviews and consensus statements. The levels of evidence for efficacy were graded according to the Canadian Network for Mood and Anxiety Treatments criteria.

RESULTS

Only psilocybin and ayahuasca have contemporary clinical trials evaluating antidepressant effects. Two pilot studies showed preliminary positive effects of single-dose ayahuasca for treatment-resistant depression (Level 3 evidence). Small randomized controlled trials of psilocybin combined with psychotherapy showed superiority to waitlist controls and comparable efficacy and safety to an active comparator (escitalopram with supportive psychotherapy) in major depressive disorder, with additional randomized controlled trials showing efficacy specifically in cancer-related depression (Level 3 evidence). There was only one open-label trial of psilocybin in treatment-resistant unipolar depression (Level 4 evidence). Small sample sizes and functional unblinding were major limitations in all studies. Adverse events associated with psychedelics, including psychological (e.g., psychotomimetic effects) and physical (e.g., nausea, emesis and headaches) effects, were generally transient.

CONCLUSIONS

There is currently only low-level evidence to support the efficacy and safety of psychedelics for major depressive disorder. In Canada, as of 2022, psilocybin remains an experimental option that is only available through clinical trials or the special access program. As such, Canadian Network for Mood and Anxiety Treatments considers psilocybin an experimental treatment and recommends its use primarily within clinical trials, or, less commonly, through the special access program in rare, special circumstances.

Risks and benefits of psilocybin use in people with bipolar disorder: An international web-based survey on experiences of 'magic mushroom' consumption

BACKGROUND

Psilocybin, the primary psychoactive component of psychedelic 'magic mushrooms', may have potential for treating depressive symptoms, and consequent applications for bipolar disorder (BD). Knowledge of the risks and benefits of psilocybin in BD is limited to case studies.

AIM

To support the design of clinical trials, we surveyed experiences of psilocybin use in people with BD.

METHODS

An international web-based survey was used to explore experiences of psilocybin use in people with a self-reported diagnosis of BD. Quantitative findings were summarised using descriptive statistics. Qualitative content analysis was used to investigate free-text responses, with a focus on positive experiences of psilocybin use.

RESULTS

A total of 541 people completed the survey (46.4% female, mean 34.1 years old). One-third (32.2%; n = 174) of respondents described new/increasing symptoms after psilocybin trips, prominently manic symptoms, difficulties sleeping and anxiety. No differences in rates of adverse events overall were observed between individuals with BD I compared to BD II. Use of emergency medical services was rare (n = 18; 3.3%), and respondents (even those who experienced adverse effects) indicated that psilocybin use was more helpful than harmful. Quantitative findings elaborated on perceived benefits, as well as the potential for psilocybin trips to contain both positively and negatively received elements.

CONCLUSIONS

The subjective benefits of psilocybin use for mental health symptoms reported by survey participants encourage further investigation of psilocybin-based treatments for BD. Clinical trials should incorporate careful monitoring of symptoms, as data suggest that BD symptoms may emerge or intensify following psilocybin use.

Acid liberalism: Silicon Valley's enlightened technocrats, and the legalization of psychedelics

The history of psychedelia within the New Left counterculture often implies a cultural alignment between psychedelics and progressive values or the promise of radical communitarian social reform. In contrast to these potentials, this paper examines Silicon Valley's engagement with psychedelics, a community which has demonstrated considerable financial and personal interests in these drugs despite promoting and advancing consistently neoliberal ends. This article studies Silicon Valley's culture of psychedelic drug use through extensive analysis of published interviews by tech industrialists, news reports, and recent studies on the tech industry's proliferation of mystical and utopian rhetoric. This work finds that psychedelics and their associated practices are given unconventional mystical meanings by some high-profile tech entrepreneurs, and that these meanings are integrated into belief systems and philosophies which are explicitly anti-democratic, individualist, and essentialist. It is argued that these mystical ideas are supported by a venture capital community which profits from the expression of disruptive utopian beliefs. These beliefs, when held by the extremely wealthy, have effects on legalization policy and the ways which psychedelics are commercialized within a legal marketplace. As Silicon Valley has put considerable resources into funding research and advocacy for psychedelics, I argue that the legalization of psychedelics will likely be operationalized to generate a near-monopoly on the market and promote further inequality in the United States that is reflective of both neoliberalism, and the essentialist beliefs of Silicon Valley functionaries.

Prevalence and associations of classic psychedelic-related seizures in a population-based sample

OBJECTIVES

Previous studies have reported links between classic psychedelic use and seizures, but little remains known about prevalence and potential risk factors of classic psychedelic-related seizures.

METHODS

Using a sample representative of the US adult population with regard to sex, age, and ethnicity (N = 2822), this study examined the prevalence and potential risk factors of classic psychedelic-related seizures, in a subsample of respondents who reported lifetime classic psychedelic use (n = 613).

RESULTS

Among those who reported lifetime classic psychedelic use, 1.5 % reported classic psychedelic-related seizures, a statistic that comports with the prevalence of epilepsy in the US population. Among those who reported seizures while using a classic psychedelic, almost half reported co-use of antidepressants, mood stabilizers, or opioid replacement therapies at the time of the seizures. Notably, classic psychedelic-related seizures were more commonly reported in certain respondents, especially those with a personal or family history of epilepsy.

CONCLUSIONS

These results suggest that classic psychedelic use could increase the risk of seizures in certain populations, particularly those with a personal or family history of epilepsy.

Adverse experiences resulting in emergency medical treatment seeking following the use of magic mushrooms

BACKGROUND

Psilocybin-containing mushrooms are used for recreational, spiritual, self-development and therapeutic purposes. However, physiologically relatively nontoxic, adverse reactions are occasionally reported.

AIMS

This study investigated the 12-month prevalence and nature of magic mushroom-related adverse reactions resulting in emergency medical treatment seeking in a global sample of people reporting magic mushroom use.

METHODS

We use data from the 2017 Global Drug Survey - a large anonymous online survey on patterns of drug use conducted between November 2016 and January 2017.

RESULTS

Out of 9233 past year magic mushroom users, 19 (0.2%) reported having sought emergency medical treatment, with a per-event risk estimate of 0.06%. Young age was the only predictor associated with higher risk of emergency medical presentations. The most common symptoms were psychological, namely anxiety/panic and paranoia/suspiciousness. Poor 'mindset', poor 'setting' and mixing substances were most reported reasons for incidents. All but one respondent returned back to normality within 24 h.

CONCLUSIONS

The results confirm psilocybin mushrooms are a relatively safe drug, with serious incidents rare and short lasting. Providing harm-reduction information likely plays a key role in preventing adverse effects. More research is needed to examine the detailed circumstances and predictors of adverse reactions including rarer physiological reactions.

Adverse experiences resulting in emergency medical treatment seeking following the use of lysergic acid diethylamide (LSD)

BACKGROUND

Recreational lysergic acid diethylamide (LSD) use is growing in popularity amid increasing research interest on psychedelics and their possible therapeutic potential yet; the potent psychotropic effects of LSD may result in adverse reactions and behaviour.

AIMS

This study aimed to investigate the 12-month incidence and nature of LSD-related adverse experiences resulting in emergency medical treatment (EMT) seeking in an international sample of people reporting LSD use.

METHODS

We use data from the 2017 Global Drug Survey - a large anonymous online survey on patterns of drug use conducted between November 2016 and January 2017.

RESULTS

Out of 10,293 past-year LSD users, 102 (1.0%) reported seeking EMT, with a per-event risk estimate of 0.2%. Younger age, comorbid mental health conditions and higher frequency of use were associated with increased risk of EMT seeking. The most common symptoms were psychological, including anxiety, panic and confusion, with the most common explanatory factors cited by respondents being poor 'setting' and 'mindset'. Most responders reported feeling back to normal within 24 h, but 11 participants experienced persistent issues after 4 weeks.

CONCLUSION

The results suggest that LSD is a relatively safe drug in recreational settings. Adverse reactions are typically short-lived, self-limiting and psychological in nature. Sub-optimal set and setting were commonly reported as suspected contributory factors. Within clinical settings, patient screening, preparatory sessions and supervision should reduce these acute risks considerably.

Psychedelics in the treatment of unipolar and bipolar depression

This is a narrative review about the role of classic and two atypical psychedelics in the treatment of unipolar and bipolar depression. Since the 1990s, psychedelics experience a renaissance in biomedical research. The so-called classic psychedelics include lysergic acid diethylamide (LSD), psilocybin, mescaline and ayahuasca. Characteristic effects like alterations in sensory perception, as well as emotion- and self-processing are induced by stimulation of serotonin 2A receptors in cortical areas. The new paradigm of psychedelic-assisted psychotherapy suggests a therapeutic framework in which a safely conducted psychedelic experience is integrated into a continuous psychotherapeutic process. First randomized, controlled trials with psilocybin show promising efficacy, tolerability, and adherence in the treatment of unipolar depression. On the other hand, classic psychedelics seem to be associated with the induction of mania, which is an important issue to consider for the design of research and clinical protocols. So called atypical psychedelics are a heterogeneous group with overlapping subjective effects but different neurobiological mechanisms. Two examples of therapeutic value in psychiatry are 3,4-methyl​enedioxy​methamphetamine (MDMA) and ketamine. Since 2020 the ketamine enantiomer esketamine has been granted international approval for treatment-resistant unipolar depression, and also first evidence exists for the therapeutic efficacy of ketamine in bipolar depression. Whether psychedelics will fulfil current expectations and find their way into broader clinical use will depend on future rigorous clinical trials with larger sample sizes. A well-considered therapeutic and legal framework will be crucial for these substances to create new treatment settings and a potential paradigm shift.

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.

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.

Phenomenology and content of the inhaled N, N-dimethyltryptamine (N, N-DMT) experience

Understanding the phenomenology and content of the inhaled N, N, dimethyltryptamine (N, N-DMT) experience is critical to facilitate and support ongoing research and therapeutic models targeting mental health conditions and central nervous system pathology. A qualitative analysis was conducted of all N, N-DMT experiences posted to the r/DMT Reddit community over a 10-year period from 2009 to 2018. A total of 3778 experiences from 3305 posts were included in this study. A median dose of N, N-DMT of 40.0 mg [interquartile range (IQR), 27.5 to 50.0] and a median experience duration of 10 min (IQR, 5.0 to 15.0) were identified. The most common somatic effects were somaesthesias (n = 1415, 37.5%) and an auditory ringing (n = 583, 15.4%). Visualizations predominantly consisted of fractals, shapes, patterns (n = 1231, 32.6%) and vivid colours (n = 953, 25.2%). Entity encounters were reported in 45.5% (n = 1719) of the experiences and involved predominantly a feminine phenotype (n = 416, 24.2%); deities (n = 293, 17.0%); aliens (n = 281, 16.3%); creature-based entities (n = 158, 9.2%, including reptilian and insectoid beings); mythological beings (n = 144, 8.4%, including machine elves); and jesters (n = 112, 6.5%). Entity interactions were predominantly positive (n = 600, 34.9% of encounters) involving benevolent, comforting, protecting, or outwardly caring interactions. A companion-type, pedagogical, or guide-type interaction was identified 32.4% of encounters (n = 557). Common typology, architecture, and structural features of the "DMT world" included descriptions of alternate or higher dimensions (n = 952, 25.2%); rooms [n = 582, 15.4%, including the "waiting room" (n = 105, 2.8%)], and a tunnel (n = 390, 10.3%). Features of mystical and ego-dissolution experiences were common. Additional rewarding aspects were identified, including a sense of familiarity and the acceptance/removal of the fear of death. Challenging and difficult responses were less frequent but also documented. Statements of profundity were identified in 232 experiences (6.1%), including pronouncing the experience or an aspect of the experience as the most "beautiful" or feeling the most "beautiful" of their life (n = 47, 1.2%). This study identified common phenomenological themes and content of naturalistic inhaled N, N-DMT experiences. Major thematic domains included (1) physical and somatic experiences; (2) visualizations and imagery; (3) entity encounters including entity phenotype, descriptors, attributes, disposition, and characteristics of the interaction; (4) typology, architectural features, structural characteristics, and scenery of the "DMT world"; (5) alerations in consciousness (including mystical experiences, out-of-body experiences, and ego-dissolution); (6) emotional responses (including positive, rewarding, difficult, and challenging); and (7) statements of profundity.

The Potential of Psychedelics for End of Life and Palliative Care

End of life and palliative care has improved in recent decades but the psychopharmacological options available to clinicians and patients in these contexts remain limited. In particular, psychological factors such as depression, existential distress, and well-being remain challenging to address with current medications. Here, we review recent research on the use of psychedelics in clinical settings with a particular focus on patients with life-threatening diagnoses. We propose that psychedelics may provide clinicians with an additional psychopharmacological treatment in the context of end of life and palliative care.

Psychedelic Therapy's Transdiagnostic Effects: A Research Domain Criteria (RDoC) Perspective

Accumulating clinical evidence shows that psychedelic therapy, by synergistically combining psychopharmacology and psychological support, offers a promising transdiagnostic treatment strategy for a range of disorders with restricted and/or maladaptive habitual patterns of emotion, cognition and behavior, notably, depression (MDD), treatment resistant depression (TRD) and addiction disorders, but perhaps also anxiety disorders, obsessive-compulsive disorder (OCD), Post-Traumatic Stress Disorder (PTSD) and eating disorders. Despite the emergent transdiagnostic evidence, the specific clinical dimensions that psychedelics are efficacious for, and associated underlying neurobiological pathways, remain to be well-characterized. To this end, this review focuses on pre-clinical and clinical evidence of the acute and sustained therapeutic potential of psychedelic therapy in the context of a transdiagnostic dimensional systems framework. Focusing on the Research Domain Criteria (RDoC) as a template, we will describe the multimodal mechanisms underlying the transdiagnostic therapeutic effects of psychedelic therapy, traversing molecular, cellular and network levels. These levels will be mapped to the RDoC constructs of negative and positive valence systems, arousal regulation, social processing, cognitive and sensorimotor systems. In summarizing this literature and framing it transdiagnostically, we hope we can assist the field in moving toward a mechanistic understanding of how psychedelics work for patients and eventually toward a precise-personalized psychedelic therapy paradigm.