Psychedelics have emerged as promising therapeutics for several psychiatric disorders. Hypotheses around their mechanisms have revolved around their partial agonism at the serotonin 2 A receptor, leading to enhanced neuroplasticity and brain connectivity changes that underlie positive mindset shifts. However, these accounts fail to recognise that the gut microbiota, acting via the gut-brain axis, may also have a role in mediating the positive effects of psychedelics on behaviour. In this review, we present existing evidence that the composition of the gut microbiota may be responsive to psychedelic drugs, and in turn, that the effect of psychedelics could be modulated by microbial metabolism. We discuss various alternative mechanistic models and emphasize the importance of incorporating hypotheses that address the contributions of the microbiome in future research. Awareness of the microbial contribution to psychedelic action has the potential to significantly shape clinical practice, for example, by allowing personalised psychedelic therapies based on the heterogeneity of the gut microbiota.

The objective of this paper is to conduct a systematic thematic review of adverse events, safety, and toxicity of traditional ayahuasca plant preparations and its main psychoactive alkaloids (dimethyltryptamine [DMT], harmine, harmaline, and tetrahydroharmine), including discussing clinical considerations (within clinical trials or approved settings). A systematic literature search of preclinical, clinical, epidemiological, and pharmacovigilance data (as well as pertinent reviews and case studies) was conducted for articles using the electronic databases of PubMed and Web of Science (to 6 July 2023) and PsycINFO, ClinicalTrials.gov, and Embase (to 21 September 2022) and included articles in English in peer-reviewed journals. Additionally, reference lists were searched. Due to the breadth of the area covered, we presented the relevant data in a thematic format. Our searches revealed 78 relevant articles. Data showed that ayahuasca or DMT is generally safe; however, some adverse human events have been reported. Animal models using higher doses of ayahuasca have shown abortifacient and teratogenic effects. Isolated harmala alkaloid studies have also revealed evidence of potential toxicity at higher doses, which may increase with co-administration with certain medications. Harmaline revealed the most issues in preclinical models. Nevertheless, animal models involving higher-dose synthetic isolates may not necessarily be able to be extrapolated to human use of therapeutic doses of plant-based extracts. Serious adverse effects are rarely reported within healthy populations, indicating an acceptable safety profile for the traditional use of ayahuasca and DMT in controlled settings. Further randomized, controlled trials with judicious blinding, larger samples, and longer duration are needed.

Psychedelics have emerged as promising therapeutics for several psychiatric disorders. Hypotheses around their mechanisms have revolved around their partial agonism at the serotonin 2 A receptor, leading to enhanced neuroplasticity and brain connectivity changes that underlie positive mindset shifts. However, these accounts fail to recognise that the gut microbiota, acting via the gut-brain axis, may also have a role in mediating the positive effects of psychedelics on behaviour. In this review, we present existing evidence that the composition of the gut microbiota may be responsive to psychedelic drugs, and in turn, that the effect of psychedelics could be modulated by microbial metabolism. We discuss various alternative mechanistic models and emphasize the importance of incorporating hypotheses that address the contributions of the microbiome in future research. Awareness of the microbial contribution to psychedelic action has the potential to significantly shape clinical practice, for example, by allowing personalised psychedelic therapies based on the heterogeneity of the gut microbiota.

Background: In the context of increasing scientific interest in the potential therapeutic use of psychedelic agents and their underlying psychotherapeutic mechanisms, we undertake the first detailed assessment of insights and life and lifestyle changes associated with ayahuasca consumption. Methods: An international cross-sectional study of ayahuasca drinkers in a variety of settings was performed (n = 8907). Bivariate analysis and multivariate linear and logistic regressions were used to explore associations between a range of covariates and insights, life changes and lifestyle changes. The least absolute shrinkage and selection operator variable selection method (LASSO) was used to select the variables most relevant for inclusion in models assessing broader wellbeing and mental health associations. Results: Insights are almost universally reported as part of the ayahuasca experience and are highly valued by drinkers and strongly predictive of subsequent beneficial life and lifestyle changes. A range of personal, vocational, religious/spiritual and health-related life changes (attributed to ayahuasca) are also commonly identified, as are various beneficial lifestyle and health behavior changes. Demographic and ayahuasca drinking variables that are predictive of such phenomena are reported, along with associations between insights, life and lifestyle changes and perceived growth in psychological wellbeing and current mental health status (Kessler 10 and SF-12 MCS). Conclusion: Insights and subsequent life and lifestyle changes appear to have a central role in the transformative effects reported by individuals consuming ayahuasca, with these occurring across contexts of use and demographic groups.

Background The potential benefits of ayahuasca on mental health conditions are well documented. This pilot study is the first to explore whether there is an association with ayahuasca use and reductions in inattention, hyperactivity and impulsivity, the core features of attention-deficit/hyperactivity disorder. Methods In this exploratory, observational pilot study, the Adult Attention-Deficit/Hyperactivity Disorder Self-Report Scale was administered to 49 adults (23 males, 24 females, two participants did not report their sex) prior to and following the completion of ayahuasca retreats facilitated by the Ayahuasca Foundation in Iquitos, Peru. Only four participants self-reported having a diagnosis of attention-deficit/hyperactivity disorder. Participants attended either an 8-day (four to five ceremonies), 2-week (six ceremonies), 3-week (eight ceremonies) or 4-week (three to 11 ceremonies) retreat. Results Inattention, hyperactivity/impulsivity and total scores significantly reduced following an ayahuasca retreat, irrespective of the length of that retreat and the number of ceremonies participants attended. Conclusions This pilot study is the first to find reductions in self-reported inattention, hyperactivity and impulsivity in a sample of mostly non-attention-deficit/hyperactivity disorder adults following the use of ayahuasca. However controlled trials are required to determine causality. Research and clinical implications are considered.

Ayahuasca is a psychoactive Amazonian plant brew. It is usually made from the Banisteriopsis caapi vine (Spruce ex Griseb. Morton, Malpighiaceae), which contains three primary harmala alkaloids, along with the leaves of Psychotria viridis (Ruiz et Pavon, Rubiaceae) in which the potent psychedelic dimethyltryptamine (DMT) is found. DMT-harmaloid concoctions have gained popularity in recent years, due to growing anecdotal and scientific reports of therapeutic benefits associated with their consumption. Ayahuasca is now ingested in a variety of different settings across the globe, from traditional ethnobotanical to so called "neo-shamanic" ceremonies. Furthermore, related preparations involving alternative sources of DMT and harmala alkaloids are becoming increasingly common as knowledge of ayahuasca continues to spread internationally. This article reviews the existing literature and draws on original qualitative data from a large cross-sectional study of ayahuasca drinkers, to propose a model of psychotherapeutic processes associated with the consumption of ayahuasca. We assert that it is these processes, facilitated by a range of neurobiological effects, that lead to beneficial mental health and wellbeing outcomes. Our proposed model identifies five key psychotherapeutic processes or effects inherent to the ayahuasca experience; somatic effects; introspection and emotional processing; increased Self-connection; increased spiritual connection, and finally the gaining of insights and new perspectives. We note some important differences in these processes compared with other classic psychedelics as well as the implications of the model for the therapeutic use of ayahuasca. Improved understanding of the psychotherapeutic processes involved with the ayahuasca experience will better equip practitioners to work with this potentially transformative concoction and enable the optimization of therapeutic treatment models for potential clinical use.

New study investigates the impact of Amazonian ayahuasca retreats on veterans, assessing its effect on brainwaves, the genome, gut microbiome and mental health

Ayahuasca is a psychedelic plant brew originating from the Amazon rainforest. It is formed from two basic components, the Banisteriopsis caapi vine and a plant containing the potent psychedelic dimethyltryptamine (DMT), usually Psychotria viridis . Here we review the history of ayahuasca and describe recent work on its pharmacology, phenomenological responses, and clinical applications. There has been a significant increase in interest in ayahuasca since the turn of the millennium. Anecdotal evidence varies significantly, ranging from evangelical accounts to horror stories involving physical and psychological harm. The effects of the brew on personality and mental health outcomes are discussed in this review. Furthermore, phenomenological analyses of the ayahuasca experience are explored. Ayahuasca is a promising psychedelic agent that warrants greater empirical attention regarding its basic neurochemical mechanisms of action and potential therapeutic application.

Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterized by increased temporal coherence at rest have been termed the Default Mode Network (DMN). The DMN has been the focus of numerous studies assessing its role in self-referencing, mind wandering, and autobiographical memories. Altered connectivity in the DMN has been associated with a range of neuropsychiatric conditions such as depression, anxiety, post-traumatic stress disorder, attention deficit hyperactive disorder, schizophrenia, and obsessive-compulsive disorder. To date, several studies have investigated how psychedelics modulate this network, but no comprehensive review, to our knowledge, has critically evaluated how major classical psychedelic agents—lysergic acid diethylamide, psilocybin, and ayahuasca—modulate the DMN. Here we present a systematic review of the knowledge base. Across psychedelics there is consistent acute disruption in resting state connectivity within the DMN and increased functional connectivity between canonical resting-state networks. Various models have been proposed to explain the cognitive mechanisms of psychedelics, and in one model DMN modulation is a central axiom. Although the DMN is consistently implicated in psychedelic studies, it is unclear how central the DMN is to the therapeutic potential of classical psychedelic agents. This article aims to provide the field with a comprehensive overview that can propel future research in such a way as to elucidate the neurocognitive mechanisms of psychedelics.

Ayahuasca is a natural psychoactive brew, used in traditional ceremonies in the Amazon basin. Recent research has indicated that ayahuasca is pharmacologically safe and its use may be positively associated with improvements in psychiatric symptoms. The mechanistic effects of ayahuasca are yet to be fully established. In this prospective naturalistic study, 63 self-selected participants took part in ayahuasca ceremonies at a retreat centre in the Peruvian Amazon. Participants undertook the Beck Depression Inventory (BDI-II), State-Trait Anxiety Inventory (STAI), Self-compassion Scale (SCS), Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM), as well as secondary measures, pre- and post-retreat and at 6-months. Participants also provided saliva samples for pre/post epigenetic analysis. Overall, a statistically significant decrease in BDI-II (13.9 vs. 6.1,p< 0.001), STAI (44.4 vs. 34.3p< 0.001) scores, and CORE-OM scores were observed (37.3 vs. 22.3p< 0.001) at post-retreat, as well as a concurrent increase in SCS (3.1 vs. 3.6,p< 0.001). Psychometric improvements were sustained, and on some measures values further decreased at 6-month follow-up, suggesting a potential for lasting therapeutic effects. Changes in memory valence were linked to the observed psychometric improvements. Epigenetic findings were equivocal, but indicated that further research in candidate genes, such as sigma non-opioid intracellular receptor 1 (SIGMAR1), is warranted. This data adds to the literature supporting ayahuasca's possible positive impact on mental health when conducted in a ceremonial context. Further investigation into clinical samples, as well as greater analyses into the mechanistic action of ayahuasca is advised.

COPYRIGHT © 2023 Blest-Hopley, Amit, O’Neill and Ru ell. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Editorial: Appropriateness and safety of using cannabinoid and psychedelic medicines as treatments for psychiatric disorders

Indigenous Amazonian shamanic ayahuasca practice is deeply rooted in nature and it is employed as an ecological mediating agent and in collective environmental decision-making processes by some of the groups that use it. Phenomenologically, the ayahuasca experience is often rich in nature-based themes and content, and its usage has been associated with eliciting shifts in perspectives and attitudes towards nature. In this proof of concept study, participation in an ayahuasca retreat in a traditional indigenous Amazonian context (with a mean of 5.85 ceremonies attended) was associated with significant increases in nature relatedness (n = 24; Cohen’s d = .51) and mindfulness (n = 38; Cohen’s d = .75), and improvements in depression (n = 47; Cohen’s d = 1.18), state anxiety (n = 47; Cohen’s d = 1.02), and trait anxiety (n = 42; Cohen’s d = .88). Furthermore, significant negative correlations were found between changes in nature relatedness and depression (r = .623, p = .001), state anxiety (r = -.542, p = .008), and trait anxiety (r = -.485, p = .022), with a significant positive correlation between change in nature relatedness and mindfulness (r = .747, p = .001). It is currently unclear if the changes seen were due to consumption of the brew, participation in ceremony, or the retreat setting itself. Although this pilot study suggests a potential therapeutic role for Amazonian ayahuasca retreats as a multidimensional intervention, further work is required to assess the role of possible mediators underlying such shifts, while evaluating to what extent these are sustained long-term.

BACKGROUND Psilocybin is being studied for use in treatment-resistant depression. METHODS In this phase 2 double-blind trial, we randomly assigned adults with treatment-resistant depression to receive a single dose of a proprietary, synthetic formulation of psilocybin at a dose of 25 mg, 10 mg, or 1 mg (control), along with psychological support. The primary end point was the change from baseline to week 3 in the total score on the Montgomery-Åsberg Depression Rating Scale (MADRS; range, 0 to 60, with higher scores indicating more severe depression). Secondary end points included response at week 3 (≥50% decrease from baseline in the MADRS total score), remission at week 3 (MADRS total score ≤10), and sustained response at 12 weeks (meeting response criteria at week 3 and all subsequent visits). RESULTS A total of 79 participants were in the 25-mg group, 75 in the 10-mg group, and 79 in the 1-mg group. The mean MADRS total score at baseline was 32 or 33 in each group. Least-squares mean changes from baseline to week 3 in the score were -12.0 for 25 mg, -7.9 for 10 mg, and -5.4 for 1 mg; the difference between the 25-mg group and 1-mg group was -6.6 (95% confidence interval [CI], -10.2 to -2.9; P<0.001) and between the 10-mg group and 1-mg group was -2.5 (95% CI, -6.2 to 1.2; P = 0.18). In the 25-mg group, the incidences of response and remission at 3 weeks, but not sustained response at 12 weeks, were generally supportive of the primary results. Adverse events occurred in 179 of 233 participants (77%) and included headache, nausea, and dizziness. Suicidal ideation or behavior or self-injury occurred in all dose groups. CONCLUSIONS In this phase 2 trial involving participants with treatment-resistant depression, psilocybin at a single dose of 25 mg, but not 10 mg, reduced depression scores significantly more than a 1-mg dose over a period of 3 weeks but was associated with adverse effects. Larger and longer trials, including comparison with existing treatments, are required to determine the efficacy and safety of psilocybin for this disorder. (Funded by COMPASS Pathfinder; EudraCT number, 2017-003288-36; ClinicalTrials.gov number, NCT03775200.).

Abstract Ayahuasca is a psychoactive plant brew containing dimethyltryptamine (DMT) and monoamine oxidase inhibitors (MAOIs). It originates from the Amazon basin, where it is used primarily for ceremonial purposes. Ayahuasca tourists are now entering certain communities seeking alternative physical or psychological healing, as well as spiritual growth. Rationale Recent evidence has shown that the similar acting psychedelic compound, psilocybin, facilitated long-term increases in trait openness following a single administration. Objectives This paper assesses the impact of ayahuasca on personality in a traditional framework catering for ayahuasca tourists. Method Within a mixed design, we examined the effect of ayahuasca on participants’ personality (measured by the NEO Personality Inventory 3 questionnaire) across time (pre- to post-ayahuasca administration, and 6-month follow-up), relative to a comparison group (who did not ingest ayahuasca). Results The results demonstrated significant increases in agreeableness pre- and post-ayahuasca administration and significant reductions in neuroticism in 24 participants, relative to the comparison group. Both of these changes were sustained at 6-month follow-up, and trait level increases were also observed in openness at this stage. Additionally, greater perceived mystical experience (measured using the Mystical Experience Questionnaire 30) was associated with increased reductions in neuroticism. Conclusions These findings, which indicate a positive mediating effect of ayahuasca on personality, support the growing literature suggesting potential therapeutic avenues for serotonergic psychedelics.

Ayahuasca is a South American psychoactive plant brew used as traditional medicine in spiritual and in cultural rituals. This is a review of the current understanding about the pharmacological mechanisms that may be interacting in ayahuasca. Searches were performed using PubMed, PsycINFO, and Web of Science databases and 16 papers were selected. As hypothesized, the primary narrative in existing research revolved around prevention of deamination of N,N-dimethyltryptamine (N,N-DMT, also referred to as DMT) by monoamine oxidase inhibitors (MAOIs) in ayahuasca. Two of the constituents, DMT and harmine, have been studied more than the secondary harmala alkaloids. At present, it is unclear whether the pharmacological interactions in ayahuasca act synergistically or additively to produce psychoactive drug effects. The included studies suggest that our current understanding of the preparation’s synergistic mechanisms is limited and that more complex processes may be involved; there is not yet enough data to determine any potential synergistic interaction between the known compounds in ayahuasca. Our pharmacological understanding of its compounds must be increased to avoid the potential risks of ayahuasca use.

Aims This heuristic study reports observations on the phenomenology of ayahuasca experiences of nine foreign tourist participants of an ayahuasca retreat in Peru. Methods Narrative interviews, reflecting individual experiences after ayahuasca “night ceremony,” have been analyzed by qualitative content analysis using a data-driven strategy in order to extract themes and categories inherent in the interviews. Previously, a demographic questionnaire was given. The dose–response connection was uncontrolled, which is typical for this naturalistic setting. Results The typical structure of spontaneously reported experiences includes: personal preparation, physical symptoms, visual phenomena, cognitive and emotional phenomena, reactions of the individual within the psychedelic “world” as well as within ordinary reality, and appraisal to the process. Emotional reactions were subsumed under pleasant (psychotherapeutic “target emotions” and hedonistic emotions) and unpleasant emotions. For a majority, the presence of psychotherapeutic target emotions seemed to involve the presence of unpleasant emotions in the same session – possibly as transitional emotional states. Conclusions This suggests that psychodynamic processes, for example, possible activation of emotional conflicts – can take place spontaneously, during ayahuasca intake in this particular setting. Some participants attributed symbolic meaning to the visionary content, which was more likely to take place in psychotherapeutically motivated clients. The specific setting influence as well as corresponding expectations of the participants in native wisdom could have considerable influence on experiences and interpretations, such as communication with entities as well as receiving personal teachings.

Our patient is a 58-year-old Ugandan woman. After her husband’s death in 1994, the patient was forced to leave her home by her late husband’s family and arrangements were made for her mother to provide care until her inevitable death. The patient suffered from multiple mental health disturbances as a result of discrimination. Socially isolated after years of self-neglect, she prepared to overdose. In 2007, she became open regarding her status after receiving psychosocial support from various sources. She opened her home as an HIV clinic with the help of a local doctor, and subsequently the majority of her psychological symptoms were resolved. This case illustrates the negative impact that stigma and discrimination can have on mental and consequently physical health, both acutely and chronically. It also highlights the importance of social and psychological support in maintaining the well-being of patients with HIV globally.