Antidepressant effects of a psychedelic experience in a large prospective naturalistic sample

Acute subjective effects of psychedelics in naturalistic group settings prospectively predict longitudinal improvements in trauma symptoms, trait shame, and connectedness among adults with childhood maltreatment histories

Studies of psychedelic use in naturalistic and clinical settings have suggested safety and mental health benefits for adults with histories of childhood maltreatment. Acute psychological mechanisms that predict therapeutic benefits in this population, however, have yet to be determined. Two common group settings of naturalistic psychedelic use - organized ceremonies and raves or other electronic dance music events - might facilitate therapeutic psychedelic effects because of the unique psychosocial environments they comprise. This prospective, longitudinal study sought to investigate 2 primary questions: first, whether adults with maltreatment histories planning to use psychedelic drugs with therapeutic intent at ceremonies or raves would see enduring psychological benefits after their experiences; and second, whether subjective dimensions of the acute psychedelic experience would be associated with lasting psychological benefits. Eighty-five participants completed self-report measures in the month before, within 2 days after, and approximately 2 months after a planned psychedelic experience with therapeutic intent at a ceremony or rave assessing childhood maltreatment history; trauma symptoms, internalized (trait) shame, and connectedness at baseline and follow-up; and various dimensions of the acute subjective psychedelic experience. Mean scores in posttraumatic stress disorder (PTSD) symptoms, complex PTSD symptoms, trait shame, social connectedness, and general connectedness significantly improved from baseline to 2-month follow-up (ds = 0.73-1.12). Longitudinal changes in outcomes significantly correlated with acute subjective effects of the psychedelic experience. These findings have implications regarding both the potential clinical benefit of psychedelic use among adults with childhood maltreatment histories as well as the psychological mechanisms of therapeutic action of psychedelics.

Contextual and experiential aspects of the psychedelic experience predicting improvement in subjective wellbeing: results from a Norwegian internet convenience sample

Background

Interest in the therapeutic effects of classical psychedelics has risen recently. However, little epidemiological knowledge exists about the use of classical psychedelics in Scandinavian countries. Additionally, there is a limited understanding of what factors drive self-reported improvement in wellbeing. The aim of this study was to investigate the relationship between the use of classical psychedelics and outcomes related to subjective wellbeing in an adult, Norwegian-speaking sample. We examined how contextual and phenomenological variables were associated with self-reported subjective wellbeing.

Methods

Using an anonymous internet survey, we recruited Norwegian speaking subjects who have had a memorable experience after taking a classic psychedelic substance. Data are presented by using descriptive statistics about the sample and two hierarchical regression analyses. The first regression analysis examined contextual variables, and the second examined variables related to acute phenomena during the experience.

Results

The survey showed that 85% of the sample reported a small to large positive change in subjective wellbeing after their experience with classical psychedelics. Integration, ego dissolution, and emotional breakthrough had a clear, positive predictive effect on the participants' self-reported subjective wellbeing. Variables with lower but significant effects were the degree of challenging experiences, settings associated with nature or ceremony, and a therapeutic or seeking intention.

Conclusion

The use of classical psychedelics leads to an increase in subjective wellbeing for the majority of the participants. This relationship seems dependent upon various experiential aspects of acute subjective drug effects. These findings should be viewed as hypothesis-generating rather than confirmatory due to the study's limitations.

A prospective ecological momentary assessment study of an ayahuasca retreat: exploring the salutary impact of acute psychedelic experiences on subacute affect and mindfulness skills in daily life

RATIONALE

To examine the acute effects of ayahuasca use and their relationship to sub-acute changes in affect and mindfulness in a non-clinical sample, addressing the need for a better understanding of ayahuasca's immediate and short-term impacts as interest in its use grows.

OBJECTIVES

Using prospective ecological assessment, this study investigates how ayahuasca used at a 4-day retreat affects positive/negative affect and mindfulness skills in daily living compared to pre-retreat. Additionally, we explore acute psychedelic experiences during the ayahuasca retreat, assessed retrospectively 1-2 days post-retreat, as potential mechanisms for theorized effects in daily living post-retreat.

METHODS

Thirty-six participants reported positive/negative affect and mindfulness skills three times daily for 5 days before and after the retreat. Baseline assessments included lifetime psychedelic experience, and post-retreat assessments covered acute ayahuasca experiences. Mixed-effect linear models were used to analyze the data.

RESULTS

Post-retreat, we observed reduced negative affect, increased positive affect, and enhanced mindfulness skills in daily living. Ayahuasca-induced acute experiences, such as time/space transcendence, emotional breakthrough and challenging experiences predicted greater subacute positive affect. Notably, none of these experiences were linked to subacute improvements in negative affect or mindfulness. No participants showed clinically significant adverse responses post-retreat, and only 5.5% exhibited some degree of potentially clinically significant deterioration in affect.

CONCLUSIONS

Ayahuasca use may lead to improvement in mood and mindfulness skills, and key acute psychedelic experiences induced by ayahuasca may be important to some of these salutary effects, positive affect in particular.

Exploring factors associated with the intensity of a mystical experience following naturalistic psychedelic use: A retrospective survey

INTRODUCTION

The intensity of the psychedelic experience has been hypothesized as the main predictor of response to a psychedelic treatment. This study aimed to investigate factors that may be associated with the intensity of mystical experiences during naturalistic psychedelic use.

METHODS

The data of this comprehensive sample were aggregated from four previous retrospective surveys, where mystical experience intensity was assessed using the mystical experience questionnaire (MEQ-30). Additional collected data included psychological flexibility levels, intentions regarding psychedelic use, substance used, subjective dosage levels, and socio-demographic information. ANOVA and linear regression were performed to identify predictors of MEQ-30 scores.

RESULTS

A total of 1657 participants were included in this study. The significant predictors of the total MEQ score were: the main motive for the psychedelic experience (with a greater impact of spiritual/religious, therapeutic, and self-exploration, compared to recreational), the type of substance used (with a higher impact for Ayahuasca and lysergic acid diethylamide than psilocybin), the subjective dosage (higher impact of very high, high, and moderate doses, compared to a very low dose), the number of psychedelic sessions, the time elapsed since the experience, and concomitant alcohol use.

CONCLUSION

This large sample study highlights significant associations between the intensity of mystical experiences during naturalistic psychedelic use and several key factors: the type of the psychedelic substance used, dosage, and set, particularly participants' intentions. Moreover, results show that concomitant alcohol use is associated with less intense psychedelic experiences, emphasizing the relevance of screening participants for substance use in research settings.

Examining differences in the effects and contexts of naturalistic psilocybin use for White participants vs. Participants of Color: A longitudinal online survey study

BACKGROUND

Psilocybin (a psychoactive compound found in "magic mushrooms" or "shrooms") has been gaining increased attention in research and popular culture as a number of clinical and observational studies have demonstrated that it may have potential for improving mental wellbeing. Relatedly, there has been a substantial uptick in naturalistic (e.g., real-world, non-clinical) psilocybin use in the United States. While a number of longitudinal studies have demonstrated that naturalistic psilocybin use is linked to positive mental health outcomes on average, few studies have examined how the effects of psilocybin and contexts for psilocybin use may differ for White populations compared to Populations of Color.

OBJECTIVE

To examine differences in health outcomes, subjective effects, and contexts of naturalistic psilocybin use in White participants compared to Participants of Color.

METHODS

This study used data from a large, online longitudinal study of individuals who planned to engage in naturalistic psilocybin use (N = 2833). We used mixed-effects models to assess whether race/ethnicity (White vs. Participant of Color) moderated associations between time (Time 2 [initial assessment point for longitudinal measures], Time 5 [2-4 weeks post-psilocybin experience, and Time 6 [2-3 months post-experience]) and outcomes related to mental health (depression, anxiety, spiritual wellbeing, cognitive flexibility, emotion regulation [expressive suppression + cognitive reappraisal]). We also used exploratory chi-squared tests to examine differences in contexts for psilocybin use as well as differences in subjective effects related to the psilocybin experience.

RESULTS

Race/ethnicity moderated the associations between time for predicting spiritual wellbeing (beta = -1.8; 95 % CI [-3.4, -0.17]; p < 0.05), cognitive flexibility (beta = -1.5 [-2.7, -0.26]; p < 0.05), and emotion regulation - expressive suppression (beta = 0.25 [0.06, 0.44]; p < 0.05) at Time 6 (but not Time 5). Additionally, Participants of Color reported minor differences in subjective effects and context for use compared to White participants (e.g., more likely to have set an intention prior to use, report time speeding up during the experience, etc.). We found reductions in anxiety and depression for both Participants of Color and White participants, and our moderation tests for these outcomes were not significant.

CONCLUSION

Race/ethnicity impacts the associations between psilocybin use and various markers of mental wellbeing. Future longitudinal studies and experimental studies with larger samples of color can further elucidate the preliminary findings from this study.

Psychedelics for the Treatment of Psychiatric Disorders: Interpreting and Translating Available Evidence and Guidance for Future Research

During the past decade, there has been extraordinary public, media, and medical research interest in psychedelics as promising therapeutics for difficult-to-treat psychiatric disorders. Short-term controlled trial data suggest that certain psychedelics are effective and safe in the treatment of major depressive disorder, treatment-resistant depression, and posttraumatic stress disorder. Preliminary evidence also supports efficacy in other psychiatric disorders (e.g., tobacco and alcohol use disorders). Notwithstanding the interest and promise of psychedelics, concerns have arisen with respect to the interpretability and translatability of study results. For example, aspects related to short- and long-term safety, abuse liability, and the essentiality of the psychedelic "trip" and psychological support are, inter alia, insufficiently characterized with psychedelic agents. The overarching aims in this overview are 1) to review methodological aspects that affect inferences and interpretation of extant psychedelic studies in psychiatric disorders, and 2) to provide guidance for future research and development of psychedelic treatment in psychiatry, critical to study interpretation and clinical implementation.

Rethinking the role of TRKB in the action of antidepressants and psychedelics

Antidepressant drugs promote neuronal plasticity, and activation of brain-derived neurotrophic factor (BDNF) signaling through its receptor neuronal receptor tyrosine kinase 2 (NTRK2 or TRKB) is among the critical steps in this process. These mechanisms are shared by typical slow-acting antidepressants, fast-acting ketamine, and psychedelic compounds, although the cellular targets of each drug differ. In this opinion article, we propose that some of these antidepressants may directly bind to TRKB and allosterically potentiate BDNF signaling, among other possible effects. TRKB activation in parvalbumin-containing interneurons disinhibits cortical networks and reactivates a juvenile-like plasticity window. Subsequent rewiring of aberrant networks, coupled with environmental stimuli, may underlie its clinical antidepressant effects. The end-to-end hypothesis proposed may stimulate the search for new treatment strategies.

What do health professionals think about implementing psilocybin-assisted therapy in palliative care for existential distress? A World Café qualitative study

OBJECTIVES

Promising studies show that psilocybin-assisted therapy relieves existential distress in patients with serious illnesses, a difficult condition to treat with current treatment options. There is growing interest in this therapy in palliative care. Canada recently amended its laws to allow physicians to request psilocybin for end-of-life distress. However, barriers to access remain. Since implementing psilocybin-assisted therapy within palliative care depends on the attitudes of healthcare providers willing to recommend it, they should be actively engaged in the broader discussion about this treatment option. We aimed (1) to identify issues and concerns regarding the acceptability of this therapy among palliative care professionals and to discuss ways of remedying them and (2) to identify factors that may facilitate access.

METHODS

A qualitative study design and World Café methodology were adopted to collect data. The event was held on April 24, 2023, with 16 palliative care professionals. The data was analyzed following an inductive approach.

RESULTS

Although participants were interested in psilocybin-assisted therapy, several concerns and needs were identified. Educational and certified training needs, medical legalization of psilocybin, more research, refinement of therapy protocols, reflections on the type of professionals dispensing the therapy, the treatment venue, and eligibility criteria for treatment were discussed.

SIGNIFICANCE OF RESULTS

Palliative care professionals consider psilocybin-assisted therapy a treatment of interest, but it generates several concerns. According to our results, the acceptability of the therapy and the expansion of its access seem interrelated. The development of guidelines will be essential to encourage wider therapy deployment.

Personal Psychedelic Experience as a Training Qualification for Facilitators: A Thematic Analysis of Qualitative Interviews with Psilocybin Experts

Emerging legal frameworks in Oregon and Colorado license facilitators to support adults receiving psychedelic services. The current legal frameworks are silent regarding facilitators' personal experience with psychedelics. An e-Delphi process recruited 36 experts with at least 5 years' experience facilitating psilocybin experiences in ceremonial settings, indigenous practices, or clinical trials. Respondents completed in-depth, semi-structured qualitative interviews via secure web links. Interviews were recorded, transcribed, and analyzed using Thematic Analysis. Experts with a mean of 15.2 (SD 13.1) years' experience providing psilocybin services expressed the importance of first-hand experience with psychedelics as a qualification for the emerging workforce. One participant questioned the necessity of personal psychedelic experience. Experts suggested that personal experience may indirectly support high-quality care because it enhances facilitators' personal wellbeing, and may help facilitators understand the complexity and nature of their clients' psychedelic experiences. Novel state-legal psychedelic paradigms create a real-world opportunity to assess associations between facilitators' personal psychedelic experience and the safety and outcomes of psychedelic services.

Psychedelic Experiences After Bereavement Improve Symptoms of Grief: The Influence of Emotional Breakthroughs and Challenging Experiences

Grief, a common reaction to loss, can frequently become problematic or impairing. Available treatments for prolonged grief disorder are promising but leave room for considerable improvement. Qualitative accounts of psychedelic experiences after bereavement reveal themes that parallel core components of prolonged grief disorder therapy. However, few studies have investigated the therapeutic potential of psychedelics for symptoms of grief. The present study surveyed recreational psychedelic users (N = 363) who had suffered a bereavement event. They reported retrospective grief symptoms before and after the psychedelic experience as well as subjective reactions to the psychedelic, including emotional breakthroughs and challenging experiences. Results indicate improvements in grief symptoms after a psychedelic experience, with a large effect size (Cohen's d = 0.83). The occurrence of emotional breakthroughs was positively associated with improvements in symptoms of grief, while the converse relation was observed for challenging experiences. Findings provide preliminary evidence that support the development of a psychedelic-assisted therapy protocol to target symptoms of grief. Psychedelic-assisted therapy might offer an alternative to current grief treatment options.

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.

Are "mystical experiences" essential for antidepressant actions of ketamine and the classic psychedelics?

The growing interest in the rapid and sustained antidepressant effects of the dissociative anesthetic ketamine and classic psychedelics, such as psilocybin, is remarkable. However, both ketamine and psychedelics are known to induce acute mystical experiences; ketamine can cause dissociative symptoms such as out-of-body experience, while psychedelics typically bring about hallucinogenic experiences, like a profound sense of unity with the universe or nature. The role of these mystical experiences in enhancing the antidepressant outcomes for patients with depression is currently an area of ongoing investigation and debate. Clinical studies have shown that the dissociative symptoms following the administration of ketamine or (S)-ketamine (esketamine) are not directly linked to their antidepressant properties. In contrast, the antidepressant potential of (R)-ketamine (arketamine), thought to lack dissociative side effects, has yet to be conclusively proven in large-scale clinical trials. Moreover, although the activation of the serotonin 5-HT2A receptor is crucial for the hallucinogenic effects of psychedelics in humans, its precise role in their antidepressant action is still under discussion. This article explores the importance of mystical experiences in enhancing the antidepressant efficacy of both ketamine and classic psychedelics.

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.

Effects of DMT on mental health outcomes in healthy volunteers

Psilocybin, a serotonergic psychedelic, is being increasingly researched in clinical studies for the treatment of psychiatric disorders. The relatively lengthy duration of oral psilocybin's acute effects (4-6 h) may have pragmatic and cost-effectiveness limitations. Here, we explored the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT), a closely related, but faster-acting psychedelic intervention, on mental health outcomes in healthy volunteers. Data is reported from two separate analyses: (1) A comparison of mental health-related variables 1 week after 7, 14, 18, and 20 mg of IV DMT versus IV saline placebo (n = 13) and, (2) A prospective dataset assessing effects before versus 2 weeks after 20 mg of IV DMT (n = 17). Mental health outcomes included measures of depression severity (QIDS-SR16), trait anxiety (STAI-T), Neuroticism (NEO-FFI), wellbeing (WHO-5), meaning in life (MLQ), optimism (LOT-R), and gratitude (GQ-6). In both the prospective and placebo-controlled datasets, significant improvements in scores of depression were found 1-2 weeks after DMT administration. Significant reductions in trait Neuroticism were only found for the placebo-controlled sample. Finally, changes in depression and trait anxiety correlated with acute peak experiences (assessed via 'Oceanic Boundlessness'). While the use of two separate cohorts in pooled analysis limits the generalizability of these correlational findings, these results suggest that DMT may reduce depressive symptomatology by inducing peak experiences. The short half-life of IV DMT and its potential for flexible dosing via controlled infusions makes it an appealing candidate for psychedelic medicine. Further research in clinical samples is needed to corroborate the therapeutic potential of DMT.

Therapeutic mechanisms of psychedelics and entactogens

Recent clinical and preclinical evidence suggests that psychedelics and entactogens may produce both rapid and sustained therapeutic effects across several indications. Currently, there is a disconnect between how these compounds are used in the clinic and how they are studied in preclinical species, which has led to a gap in our mechanistic understanding of how these compounds might positively impact mental health. Human studies have emphasized extra-pharmacological factors that could modulate psychedelic-induced therapeutic responses including set, setting, and integration-factors that are poorly modelled in current animal experiments. In contrast, animal studies have focused on changes in neuronal activation and structural plasticity-outcomes that are challenging to measure in humans. Here, we describe several hypotheses that might explain how psychedelics rescue neuropsychiatric disease symptoms, and we propose ways to bridge the gap between human and rodent studies. Given the diverse pharmacological profiles of psychedelics and entactogens, we suggest that their rapid and sustained therapeutic mechanisms of action might best be described by the collection of circuits that they modulate rather than their actions at any single molecular target. Thus, approaches focusing on selective circuit modulation of behavioral phenotypes might prove more fruitful than target-based methods for identifying novel compounds with rapid and sustained therapeutic effects similar to psychedelics and entactogens.

The relation between naturalistic use of psychedelics and perception of emotional stimuli: An event-related potential study comparing non-users and experienced users of classic psychedelics

BACKGROUND

Previous research has suggested that controlled administration of psychedelic substances can modulate emotional reactivity, enhancing positive and diminishing negative emotions. However, it is unclear whether similar effects are associated with using psychedelics in less-controlled naturalistic environments.

AIMS

This cross-sectional study investigated the neural markers associated with the perception of emotional stimuli in individuals with extensive experience of naturalistic psychedelic use (15 or more lifetime experiences), comparing them to non-users.

METHODS

Electroencephalography (EEG) signals were recorded from two groups: experienced psychedelics users (N = 56) and non-users (N = 55). Participants were presented with facial images depicting neutral or emotional expressions (anger, sadness, and happiness). Event-related potential (ERP) components were analyzed as indices of emotional reactivity.

RESULTS

Psychedelic users were characterized by significantly lower amplitudes of the N200 component in response to fearful faces, in comparison to non-users. In addition, interaction effects between Group and Emotional expression were observed on N170 and N200 amplitudes, indicating group differences in the processing of fearful faces. However, no significant between-group differences emerged in the analysis of later ERP components associated with attention and cognitive processes (P200 and P300).

CONCLUSIONS

The results suggest that naturalistic use of psychedelics may be linked to reduced reactivity to emotionally negative stimuli at the early and automatic processing stages. Our study contributes to a better understanding of the effects related to using psychedelics in naturalistic contexts.

UNRAVELing the synergistic effects of psilocybin and environment on brain-wide immediate early gene expression in mice

The effects of context on the subjective experience of serotonergic psychedelics have not been fully examined in human neuroimaging studies, partly due to limitations of the imaging environment. Here, we administered saline or psilocybin to mice in their home cage or an enriched environment, immunofluorescently-labeled brain-wide c-Fos, and imaged iDISCO+ cleared tissue with light sheet fluorescence microscopy (LSFM) to examine the impact of environmental context on psilocybin-elicited neural activity at cellular resolution. Voxel-wise analysis of c-Fos-immunofluorescence revealed clusters of neural activity associated with main effects of context and psilocybin-treatment, which were validated with c-Fos+ cell density measurements. Psilocybin increased c-Fos expression in subregions of the neocortex, caudoputamen, central amygdala, and parasubthalamic nucleus while it decreased c-Fos in the hypothalamus, cortical amygdala, striatum, and pallidum in a predominantly context-independent manner. To gauge feasibility of future mechanistic studies on ensembles activated by psilocybin, we confirmed activity- and Cre-dependent genetic labeling in a subset of these neurons using TRAP2+/-;Ai14+ mice. Network analyses treating each psilocybin-sensitive cluster as a node indicated that psilocybin disrupted co-activity between highly correlated regions, reduced brain modularity, and dramatically attenuated intermodular co-activity. Overall, our results indicate that main effects of context and psilocybin were robust, widespread, and reorganized network architecture, whereas context×psilocybin interactions were surprisingly sparse.

Case analysis of long-term negative psychological responses to psychedelics

Recent controversies have arisen regarding claims of uncritical positive regard and hype surrounding psychedelic drugs and their therapeutic potential. Criticisms have included that study designs and reporting styles bias positive over negative outcomes. The present study was motivated by a desire to address this alleged bias by intentionally focusing exclusively on negative outcomes, defined as self-perceived 'negative' psychological responses lasting for at least 72 h after psychedelic use. A strong justification for this selective focus was that it might improve our ability to capture otherwise missed cases of negative response, enabling us to validate their existence and better examine their nature, as well as possible causes, which could inspire risk-mitigation strategies. Via advertisements posted on social media, individuals were recruited who reported experiencing negative psychological responses to psychedelics (defined as classic psychedelics plus MDMA) lasting for greater than 72 h since using. Volunteers were directed to an online questionnaire requiring quantitative and qualitative input. A key second phase of this study involved reviewing all of the submitted cases, identifying the most severe-e.g., where new psychiatric diagnoses were made or pre-existing symptoms made worse post psychedelic-use-and inviting these individuals to participate in a semi-structured interview with two members of our research team, during which participant experiences and backgrounds were examined in greater depth. Based on the content of these interviews, a brief summary of each case was compiled, and an explorative thematic analysis was used to identify salient and consistent themes and infer common causes. 32 individuals fully completed an onboarding questionnaire (56% male, 53% < age 25); 37.5% of completers had a psychiatric diagnosis that emerged after their psychedelic experience, and anxiety symptoms arose or worsened in 87%. Twenty of the seemingly severer cases were invited to be interviewed; of these, 15 accepted an in-depth interview that lasted on average 60 min. This sample was 40% male, mean age = 31 ± 7. Five of the 15 (i.e., 33%) reported receiving new psychiatric diagnoses after psychedelic-use and all fifteen reported the occurrence or worsening of psychiatric symptoms post use, with a predominance of anxiety symptoms (93%). Distilling the content of the interviews suggested the following potential causal factors: unsafe or complex environments during or surrounding the experience, unpleasant acute experiences (classic psychedelics), prior psychological vulnerabilities, high- or unknown drug quantities and young age. The current exploratory findings corroborate the reality of mental health iatrogenesis via psychedelic-use but due to design limitations and sample size, cannot be used to infer on its prevalence. Based on interview reports, we can infer a common, albeit multifaceted, causal mechanism, namely the combining of a pro-plasticity drug-that was often 'over-dosed'-with adverse contextual conditions and/or special psychological vulnerability-either by young age or significant psychiatric history. Results should be interpreted with caution due to the small sample size and selective sample and study focus.

Associations between the use of psychedelics and other recreational drugs with mental health and resilience during the COVID-19 pandemic

The large-scale disruption to peoples' daily lives during the COVID-19 pandemic provides a context for examining whether use of substances such as psychedelics in a naturalistic (outside of a controlled environment) setting, is associated with better mental wellbeing and resilience relative to those who use other drugs, or who do not use drugs at all. We interrogate data from the Great British Intelligence Test and identify that 7.8% out of N = 30,598 unique respondents used recreational drugs inclusive of psychedelics, cannabis, cocaine, and MDMA during the COVID-19 pandemic. Recruitment materials did not mention drug use would be surveyed, thereby enabling us to model the relationship with mood and resilience in people who had not specifically self-selected themselves for a 'drug' study. We report that people form clusters, characterized by different real-world patterns of drug use, and the majority of psychedelics users also use cannabis. However, a subset of cannabis users do not use psychedelics, enabling a subtractive comparison. Those who primarily used psychedelics and cannabis during the COVID-19 pandemic had worse mood self-assessment and resilience scores compared to those who never used drugs or primarily used cannabis. This pattern was also evident for other recreational drug use clusters, except for those who primarily used MDMA and cannabis, who had better mood but were of too low incidence to have confidence in this estimate. These findings cast light on the significant differences in mental wellbeing between users of different drugs and the non-user population during a global-crisis and call for future research to explore the pharmacological, contextual and cultural variables associated with these differences, their generalisability and causal links with greater precision.

The integrated treatment of eating disorders, posttraumatic stress disorder, and psychiatric comorbidity: a commentary on the evolution of principles and guidelines

Psychiatric comorbidity is the norm in the assessment and treatment of eating disorders (EDs), and traumatic events and lifetime PTSD are often major drivers of these challenging complexities. Given that trauma, PTSD, and psychiatric comorbidity significantly influence ED outcomes, it is imperative that these problems be appropriately addressed in ED practice guidelines. The presence of associated psychiatric comorbidity is noted in some but not all sets of existing guidelines, but they mostly do little to address the problem other than referring to independent guidelines for other disorders. This disconnect perpetuates a "silo effect," in which each set of guidelines do not address the complexity of the other comorbidities. Although there are several published practice guidelines for the treatment of EDs, and likewise, there are several published practice guidelines for the treatment of PTSD, none of them specifically address ED + PTSD. The result is a lack of integration between ED and PTSD treatment providers, which often leads to fragmented, incomplete, uncoordinated and ineffective care of severely ill patients with ED + PTSD. This situation can inadvertently promote chronicity and multimorbidity and may be particularly relevant for patients treated in higher levels of care, where prevalence rates of concurrent PTSD reach as high as 50% with many more having subthreshold PTSD. Although there has been some progress in the recognition and treatment of ED + PTSD, recommendations for treating this common comorbidity remain undeveloped, particularly when there are other co-occurring psychiatric disorders, such as mood, anxiety, dissociative, substance use, impulse control, obsessive-compulsive, attention-deficit hyperactivity, and personality disorders, all of which may also be trauma-related. In this commentary, guidelines for assessing and treating patients with ED + PTSD and related comorbidity are critically reviewed. An integrated set of principles used in treatment planning of PTSD and trauma-related disorders is recommended in the context of intensive ED therapy. These principles and strategies are borrowed from several relevant evidence-based approaches. Evidence suggests that continuing with traditional single-disorder focused, sequential treatment models that do not prioritize integrated, trauma-focused treatment approaches are short-sighted and often inadvertently perpetuate this dangerous multimorbidity. Future ED practice guidelines would do well to address concurrent illness in more depth.

Effects of serotonergic psychedelics on mitochondria: Transdiagnostic implications for mitochondria-related pathologies

The use of serotonergic psychedelics has gained increasing attention in research, clinical practice and society. Growing evidence suggests fast-acting, transdiagnostic health benefits of these 5-hydroxytryptamine 2A receptor agonists. Here, we provide a brief overview of their benefits for psychological, cardiovascular, metabolic, neurodegenerative, and immunological pathologies. We then review their effect on mitochondria including mitochondrial biogenesis, functioning and transport. Mitochondrial dysregulation is a transdiagnostic mechanism that contributes to the aforementioned pathologies. Hence, we postulate that psychedelic-induced effects on mitochondria partially underlie their transdiagnostic benefits. Based on this assumption, we propose new treatment indications for psychedelics and that the health benefits induced by psychedelics depend on patient-specific mitochondrial dysregulation.

Eating disorder patients with and without PTSD treated in residential care: discharge and 6-month follow-up results

INTRODUCTION

We studied whether provisional posttraumatic stress disorder (PTSD) moderated discharge (DC) and 6-month follow-up (FU) outcomes of multi-modal, integrated eating disorder (ED) residential treatment (RT) based upon principles of cognitive processing therapy (CPT).

METHODS

ED patients [N = 609; 96% female; mean age (± SD) = 26.0 ± 8.8 years; 22% LGBTQ +] with and without PTSD completed validated assessments at admission (ADM), DC and 6-month FU to measure severity of ED, PTSD, major depressive disorder (MDD), state-trait anxiety (STA) symptoms, and eating disorder quality of life (EDQOL). We tested whether PTSD moderated the course of symptom change using mixed models analyses and if ED diagnosis, ADM BMI, age of ED onset and LGBTQ + orientation were significant covariates of change. Number of days between ADM and FU was used as a weighting measure.

RESULTS

Despite sustained improvements with RT in the total group, the PTSD group had significantly higher scores on all measures at all time points (p ≤ .001). Patients with (n = 261) and without PTSD (n = 348) showed similar symptom improvements from ADM to DC and outcomes remained statistically improved at 6-month FU compared to ADM. The only significant worsening observed between DC and FU was with MDD symptoms, yet all measures remained significantly lower than ADM at FU (p ≤ .001). There were no significant PTSD by time interactions for any of the measures. Age of ED onset was a significant covariate in the EDI-2, PHQ-9, STAI-T, and EDQOL models such that an earlier age of ED onset was associated with a worse outcome. ADM BMI was also a significant covariate in the EDE-Q, EDI-2, and EDQOL models, such that higher ADM BMI was associated with a worse ED and quality of life outcome.

CONCLUSIONS

Integrated treatment approaches that address PTSD comorbidity can be successfully delivered in RT and are associated with sustained improvements at FU. Improving strategies to prevent post-DC recurrence of MDD symptoms is an important and challenging area of future work.

Canalization and plasticity in psychopathology

This theoretical article revives a classical bridging construct, canalization, to describe a new model of a general factor of psychopathology. To achieve this, we have distinguished between two types of plasticity, an early one that we call 'TEMP' for 'Temperature or Entropy Mediated Plasticity', and another, we call 'canalization', which is close to Hebbian plasticity. These two forms of plasticity can be most easily distinguished by their relationship to 'precision' or inverse variance; TEMP relates to increased model variance or decreased precision, whereas the opposite is true for canalization. TEMP also subsumes increased learning rate, (Ising) temperature and entropy. Dictionary definitions of 'plasticity' describe it as the property of being easily shaped or molded; TEMP is the better match for this. Importantly, we propose that 'pathological' phenotypes develop via mechanisms of canalization or increased model precision, as a defensive response to adversity and associated distress or dysphoria. Our model states that canalization entrenches in psychopathology, narrowing the phenotypic state-space as the agent develops expertise in their pathology. We suggest that TEMP - combined with gently guiding psychological support - can counter canalization. We address questions of whether and when canalization is adaptive versus maladaptive, furnish our model with references to basic and human neuroscience, and offer concrete experiments and measures to test its main hypotheses and implications. This article is part of the Special Issue on "National Institutes of Health Psilocybin Research Speaker Series".

Personal Psychedelic Use Is Common Among a Sample of Psychedelic Therapists: Implications for Research and Practice

BACKGROUND

An emerging controversy in psychedelic therapy regards the appropriateness or necessity of psychedelic therapists having personal experience using psychedelics themselves. Although there are a number of potential advantages and disadvantages to personal use among psychedelic therapists, no studies to date have measured their use or other aspects of their training.

MATERIALS AND METHODS

First, we broadly review the literature on experiential learning in psychotherapy and psychiatry as well as the history of personal use of psychedelics by professionals. We then report on the results of a survey that was sent to all 145 therapists associated with Usona Institute's Phase II clinical trial of psilocybin for major depressive disorder. Thirty-two of these individuals (22% response rate) participated in the survey.

RESULTS

We found that experiential learning is common in psychotherapy but not in psychiatry, meaning psychedelic therapy straddles two different traditions. In our survey, the majority of psychedelic therapists identified as white, female, and having doctoral degrees. Most of the sample had personal experience with at least one serotonergic psychedelic (28/32; 88%), with psilocybin being most common (26/32; 81%; median number of uses = 2-10; median last use 6-12 months before survey). Participants had myriad intentions for using psychedelics (e.g., personal development, spiritual growth, fun, curiosity). All respondents endorsed favorable views regarding the efficacy of psilocybin therapy.

CONCLUSION

Personal experience with psychedelics was notably common in this sample of psychedelic therapists, but the study was limited by a low response rate and a lack of diversity among participants. Future research is needed to address these limitations as well as to identify whether personal experience with psychedelics contributes to therapists' competency or introduces bias to the field. Nonetheless, these findings are the first to delineate the personal use of psychedelics among professionals and can inform a pressing debate for the field.

UNRAVELing the synergistic effects of psilocybin and environment on brain-wide immediate early gene expression in mice

The effects of context on the subjective experience of serotonergic psychedelics have not been fully examined in human neuroimaging studies, partly due to limitations of the imaging environment. Here, we administered saline or psilocybin to mice in their home cage or an enriched environment, immunofluorescently-labeled brain-wide c-Fos, and imaged cleared tissue with light sheet microscopy to examine the impact of context on psilocybin-elicited neural activity at cellular resolution. Voxel-wise analysis of c-Fos-immunofluorescence revealed differential neural activity, which we validated with c-Fos + cell density measurements. Psilocybin increased c-Fos expression in the neocortex, caudoputamen, central amygdala, and parasubthalamic nucleus and decreased c-Fos in the hypothalamus, cortical amygdala, striatum, and pallidum. Main effects of context and psilocybin-treatment were robust, widespread, and spatially distinct, whereas interactions were surprisingly sparse.