Personality, psychopathology, life attitudes and neuropsychological performance among ritual users of Ayahuasca: a longitudinal study

Cognitive functioning associated with acute and subacute effects of classic psychedelics and MDMA - a systematic review and meta-analysis

Classic psychedelics and MDMA have a colorful history of recreational use, and both have recently been re-evaluated as tools for the treatment of psychiatric disorders. Several studies have been carried out to assess potential long-term effects of a regular use on cognition, delivering distinct results for psychedelics and MDMA. However, to date knowledge is scarce on cognitive performance during acute effects of those substances. In this systematic review and meta-analysis, we investigate how cognitive functioning is affected by psychedelics and MDMA during the acute drug effects and the sub-acute ("afterglow") window. Our quantitative analyses suggest that acute cognitive performance is differentially affected by psychedelics when compared to MDMA: psychedelics impair attention and executive function, whereas MDMA primarily affects memory, leaving executive functions and attention unaffected. Our qualitative analyses reveal that executive functioning and creativity may be increased during a window of at least 24 h after the acute effects of psychedelics have subsided, whereas no such results have been observed for MDMA. Our findings may contribute to inform recommendations on harm reduction for recreational settings and to help fostering differential approaches for the use of psychedelics and MDMA within a therapeutic framework.

Long-term ayahuasca use is associated with preserved global cognitive function and improved memory: a cross-sectional study with ritual users

Although several studies have been conducted to elucidate the relationship between psychedelic consumption and cognition, few have focused on understanding the long-term use influence of these substances on these variables, especially in ritualistic contexts.  To verify the influence of ritualistic ayahuasca consumption on the cognition of experienced ayahuasca religious users (> 20 years) and beginners (< 3 years), which participated in rituals of the Centro Luz Divina (CLD), a Santo Daime church in Brazil. Observational, descriptive, and cross-sectional study was carried out in which 48 people participated divided into three groups: (a) experienced ayahuasca users (n = 16), (b) beginner ayahuasca users (n = 16) and (c) control group (n = 16). All groups were matched by sex, age, and education and contained 8 women and 8 men. Cognition was assessed with the WASI (intelligence quotient), Digit Span (verbal working memory), Corsi Block-Tapping Task (visuospatial-related and working memory), Rey-Osterrieth Complex Figure test (visual perception, immediate memory), and Wisconsin Card Sorting and Five Digit Test (executive functions). Groups were homogenous in terms of sociodemographic characteristics, with participants presenting average intellectual performance. There was no evidence of cognitive decline amongst ayahuasca users. The experienced group showed higher scores compared to the less experienced group in the Digit Span and Corsi Block-Tapping tasks, which assess working verbal and visuospatial memories respectively. We confirmed the botanical identities of Psychotria viridis and Banisteriopsis caapi and the presence of the alkaloids both in the plants and in the brew. Short and long-term ayahuasca consumption does not seem to alter human cognition, while long-term use seems to be associated with improvements in aspects of working memory when compared with short-term use.

Long-term benefits to psychological health and well-being after ceremonial use of Ayahuasca in Middle Eastern and North African immigrants and refugees

Background

Refugees and immigrants can experience complex stressors from the process of immigration that can have lasting and severe long-term mental health consequences. Experiences after ayahuasca ingestion are shown to produce positive effects on psychological wellbeing and mental health, including anecdotal reports of improved symptoms of trauma and related disorders. However, data on the longitudinal health impact of naturalistic ayahuasca use in Middle Eastern and North African (MENA) immigrant and refugee populations is limited.

Aims

The current longitudinal online survey study was conducted to gather prospective data on ceremonial ayahuasca use in a group (N = 15) of primarily female MENA immigrants and refugees and to provide further insight into the patterns and outcomes surrounding that use. The study sought to assess self-reported changes in physical and mental health, well-being, and psychological functioning, examine relationships between aspects of individual mindset (e.g., psychedelic preparedness) prior to ayahuasca use and observed outcomes during (e.g., subjective drug effects) and afterwards (i.e., persisting effects), characterize risks and negative experiences, and describe trauma exposure and personal history.

Results/Outcomes

Our findings revealed ceremonial use of ayahuasca is associated with significant improvements in mental health, well-being, and psychological functioning, including reductions in depression, anxiety, and shame, and increases in cognitive reappraisal and self-compassion. Most participants reported no lasting adverse effects and experienced notable positive behavioral changes persisting months after ingestion.

Conclusion/Interpretation

While preliminary, results suggest naturalistic ayahuasca use might hold therapeutic potential for MENA populations exposed to trauma prior to and during the process of migration.

Cannabis and Public Health: A Study Assessing Regular Cannabis Users Through Health Indicators

Background and Objective: An increasing number of countries are deciding to regulate the medicinal and/or recreational use of cannabis (Cannabis sativa L.). However, there is a lack of information on the impact of regular consumption of this substance on public health. In this study, for the first time, regular cannabis consumers in Spain were assessed using health indicators, comparing these data with the general population. Methods: Various items of the Enquesta de Salut de Catalunya (ESCA) and other items related to cannabis use were selected to build a survey and administer it to a representative sample of regular cannabis users in Catalonia. Results: Most of the indicators did not show any deterioration in the health of regular cannabis users compared with the general population. It was observed that users suffered from more sleep problems and about 40% of the sample would like to discontinue cannabis use, suggesting a dependence pattern. About 30% of the sample was able to discontinue the use of prescription medications because of cannabis. Social support and sleep problems, and not cannabis use, were predictors of depression and well-being scores. Conclusions: It seems that regular cannabis use, despite contributing to problems related to sleep quality or dependence, does not have a negative impact on public health in a manner detectable using health indicators.

Validation of the Danish Translation of the Revised Mystical Experience Questionnaire (MEQ30) and Possible Impact of Setting, Dose and Intention

Research suggests positive changes in both well-being and psychiatric symptoms following a psychedelic experience. One explanation may be the ability of psychedelic compounds to occasion mystical-type experiences. The Revised Mystical Experiences Questionnaire (MEQ30) is designed to assess the intensity and quality of such experiences. We examined the validity, reliability, and factor structure of a Danish translation of the MEQ30 in one sample of healthy volunteers receiving psilocybin in a laboratory setting (N = 47) and two samples of recreative users of psychedelics, in which MEQ30 was reported retrospectively through an online survey based on their most recent experience with psilocybin (N = 834) or their most memorable experience with any psychedelic (N = 500). We conducted a confirmatory factor analysis of the previously suggested factor structures, calculated alpha and omega, and tested the associations between MEQ30 total score and setting, intention and dose. We found excellent internal reliability estimates across all samples, and confirmatory factor analysis showed that a four-factor structure, had the best, fair fit to the data. We further found that the MEQ30 total score was correlated with dose and a spiritual/religious intention, but not with setting. The Danish MEQ30 seems to be a valid tool for accessing mystical-type experiences among Danish-speaking individuals.

Psychedelic therapies reconsidered: compounds, clinical indications, and cautious optimism

The clinical investigation of psychedelic medicines has blossomed over the last 5 years. Data from a Phase 3 industry trial and a multicenter Phase 2 industry trial, in addition to multiple early phase investigator-initiated and industry trials, have now been published in peer-reviewed journals. This narrative review summarizes both the recent data and the current clinical trials that are being conducted with various classes of "psyche-manifesting" substances, which may prove beneficial in the treatment of a broad range of conditions. Methodological considerations, unique challenges, and next steps for research are discussed in keeping with the uniquely "experiential" nature of these therapies.

Ayahuasca: A review of historical, pharmacological, and therapeutic aspects

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.

Spiritual Well-Being Among Users and Non-Users of Psychedelics: A Cross-Sectional Study

This study evaluated the psychometric properties of the Spiritual Well-Being Scale (SWBS) in a Brazilian sample. We analyzed spiritual well-being, defined as existential well-being (EWB) and religious well-being (RWB), among individuals with varying religious and spiritual experiences, both users and non-users of psychedelics. The online cross-sectional survey was conducted in Brazil, from April to June 2022. The psychometric analyses demonstrated reliability and validity based on the internal structure and the relationship with satisfactory external variables concerning the RWB and EWB factors of the SWBS. Validity evidence was shown for both factors (RWB, EWB) with adequate reliability ratings. However, the RWB factor, which was entirely replicated, demonstrated the best group differentiation and internal consistency. Although both factors showed validity, the RWB factor exhibited superior psychometric indices for validity, group discrimination, and reliability. Regarding psychedelics, the association with RWB and EWB demonstrates a U-shaped pattern, as participants who never use these substances typically exhibit higher RWB and EWB indices, succeeded by frequent users. This finding underscores the need for additional studies to further explore the intricate interplay between psychedelics and spiritual well-being.

A quantitative textual analysis of the subjective effects of ayahuasca in naïve users with and without depression

Ayahuasca is a brew with psychoactive properties that has been used as an entheogen for centuries, with more recent studies suggesting it is a promising treatment for some clinical disorders. Although there is an emerging scientific literature on its effects, to the best of our knowledge no study has explored the self-reported experiences of first-time ayahuasca users with quantitative textual analysis tools. Accordingly, the current study aimed to analyze the subjective experience of naive individuals with depression and healthy controls after consuming ayahuasca. For this purpose, responses from a subsample of participants from a previous clinical trial to open-ended questions regarding their experience with ayahuasca underwent textual analysis. Data from nine patients with treatment-resistant depression and 20 healthy individuals were included, and quantitative textual analysis was performed using IRaMuTeQ 0.7 alpha 2 and R 3.1.2. The analysis identified five clusters: alterations in the state of consciousness, cognitive changes, somatic alterations, auditory experiences, and visual perceptual content. Additionally, findings suggest specific features of the experience of people with depression with ayahuasca, such as increased aversive bodily reactions. The results are consistent with previous findings indicating central axes of the psychedelic experience, and may inform therapeutic approaches using ayahuasca.

When the Trial Ends: The Case for Post-Trial Provisions in Clinical Psychedelic Research

The ethical value-and to some scholars, necessity-of providing trial patients with post-trial access (PTA) to an investigational drug has been subject to significant attention in the field of research ethics. Although no consensus has emerged, it seems clear that, in some trial contexts, various factors make PTA particularly appropriate. We outline the atypical aspects of psychedelic clinical trials that support the case for introducing the provision of PTA within research in this field, including the broader legal status of psychedelics, the nature of the researcher-therapist/participant relationship, and the extended time-frame of the full therapeutic process. As is increasingly understood, the efficacy of psychedelic-assisted psychotherapy is driven as much by extrapharmacological elements and the cultural therapeutic container as by the drug itself. As such, we also advocate for a refocusing of attention from post-trial access to a broader concept encompassing other elements of post-trial care. We provide an overview of some of the potential post-trial care provisions that may be appropriate in psychedelic clinical trials. Although the World Medical Association's Declaration of Helsinki calls on researchers, sponsors, and governments to make provisions for post-trial access, such provision may feel impracticable or out-of-reach within psychedelic trials that are already constrained by a high resource demand and significant bureaucratic burden. We show how conceiving of post-trial provision as an integral site of the research process, and an appropriate destination for research funding, will serve to develop the infrastructure necessary for the post-legalisation psychedelic medicine ecosystem.

Ayahuasca, Personality and Acute Psychological Effects in Neo-Shamanic and Religious Settings in Uruguay

This study is an interdisciplinary research into Uruguayan ayahuasca users belonging to one neo-shamanic and one Santo Daime group. The study involved the chemical analysis of ayahuasca samples, an ethnographic description of the two traditions and rituals, and the application of psychometric scales to measure personality differences, and the acute psychological effects during an ayahuasca ritual. Personality measurements showed lower scores for Santo Daime in Neuroticism-Anxiety, Dependence, Low Self-Esteem, Anger and Restlessness. These differences may be related to the presence of participants under treatment in the neo-shamanic group and/or to the protective effects of a church religion such as Santo Daime. Regarding acute effects, the neo-shamanic group showed higher scores in Somesthesia and Perception, which can be related to the high-arousal ritual setting. Chemical analysis for the ayahuasca samples showed a typical composition of alkaloids. No adulterants were found. The sample from the neo-shamanic group displayed a higher β-carbolines:DMT ratio compared to the Santo Daime sample, which could be related to the higher effects observed for Somesthesia for the neo-shamanic group. Significant positive correlations between some personality traits and acute effects were found only in the neo-shamanic group, which may be related to the more individualistic approach of this tradition.

Cortical structural differences following repeated ayahuasca use hold molecular signatures

Introduction

Serotonergic psychedelics such as ayahuasca are reported to promote both structural and functional neural plasticity via partial 5-HT2A agonism. However, little is known about how these molecular mechanisms may extend to repeated psychedelic administration in humans, let alone neuroanatomy. While early evidence suggests localised changes to cortical thickness in long-term ayahuasca users, it is unknown how such findings may be reflected by large-scale anatomical brain networks comprising cytoarchitecturally complex regions.

Methods

Here, we examined the relationship between cortical gene expression markers of psychedelic action and brain morphometric change following repeated ayahuasca usage, using high-field 7 Tesla neuroimaging data derived from 24 members of an ayahuasca-using church (Santo Daime) and case-matched controls.

Results

Using a morphometric similarity network (MSN) analysis, repeated ayahuasca use was associated with a spatially distributed cortical patterning of both structural differentiation in sensorimotor areas and de-differentiation in transmodal areas. Cortical MSN remodelling was found to be spatially correlated with dysregulation of 5-HT2A gene expression as well as a broader set of genes encoding target receptors pertinent to ayahuasca's effects. Furthermore, these associations were similarly interrelated with altered gene expression of specific transcriptional factors and immediate early genes previously identified in preclinical assays as relevant to psychedelic-induced neuroplasticity.

Conclusion

Taken together, these findings provide preliminary evidence that the molecular mechanisms of psychedelic action may scale up to a macroscale level of brain organisation in vivo. Closer attention to the role of cortical transcriptomics in structural-functional coupling may help account for the behavioural differences observed in experienced psychedelic users.

Longitudinal and transcultural assessment of the relationship between hallucinogens, well-being, and post-traumatic growth during the COVID-19 pandemic

The COVID-19 pandemic has had a devastating impact on the health and wellbeing of the global population. This paper presents the results of a longitudinal transcultural study that was begun at the peak of the pandemic (in April, 2020). An online survey was used to collect data from English-, Spanish-, and Portuguese-speaking participants. The survey collected information about sociodemographics, lifestyle activities, COVID-19-related circumstances, and drug use (with an emphasis on hallucinogenic drugs), as well as involving psychometric questionnaires. Users of hallucinogenic drugs had higher psychological well-being and lower scores on psychopathology scales, both at baseline and during follow-ups. This difference was larger when users were distinguished by frequency of use, as regular users scored higher on psychological well-being and lower on psychopathology scales. Subjects with more psychological distress had lower scores for all scales of post-traumatic growth, but if they were regular hallucinogens users, they had higher scores for post-traumatic growth. When comparing the results between cultural contexts, heterogeneous results were obtained. There were more English-speaking regular users of hallucinogenic drugs. Further research should analyse the potential role of hallucinogens in large-scale catastrophes, with a special focus on post-traumatic growth.

"In vivo biosynthesis of N,N-dimethyltryptamine, 5-MeO-N,N-dimethyltryptamine, and bufotenine in E.coli"

N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and 5-hydroxy-N,N-dimethyltryptamine (bufotenine) are psychedelic tryptamines found naturally in both plants and animals and have shown clinical potential to help treat mental disorders, such as anxiety and depression. Advances in both metabolic and genetic engineering make it possible to engineer microbes as cell factories to produce DMT and its aforementioned derivatives to meet demand for ongoing clinical study. Here, we present the development of a biosynthetic production pathway for DMT, 5-MeO-DMT, and bufotenine in the model microbe Escherichia coli. Through the application of genetic optimization techniques and process optimization in benchtop fermenters, the in vivo production of DMT in E. coli was observed. DMT production with tryptophan supplementation reached maximum titers of 74.7 ± 10.5 mg/L under fed batch conditions in a 2-L bioreactor. Additionally, we show the first reported case of de novo production of DMT (from glucose) in E. coli at a maximum titer of 14.0 mg/L and report the first example of microbial 5-MeO-DMT and bufotenine production in vivo. This work provides a starting point for further genetic and fermentation optimization studies with the goal to increase methylated tryptamine production metrics to industrially competitive levels.

Interactive Effects of Ayahuasca and Cannabidiol in Social Cognition in Healthy Volunteers: A Pilot, Proof-of-Concept, Feasibility, Randomized-Controlled Trial

BACKGROUND

Serotonergic hallucinogens and cannabinoids may alter the recognition of emotions in facial expressions (REFE). Cannabidiol (CBD) attenuates the psychoactive effects of the cannabinoid-1 agonist tetrahydrocannabinol. Ayahuasca is a dimethyltryptamine-containing hallucinogenic decoction. It is unknown if CBD may moderate and attenuate the effects of ayahuasca on REFE.

PROCEDURES

Seventeen healthy volunteers participated in a 1-week preliminary parallel-arm, randomized controlled trial for 18 months. Volunteers received a placebo or 600 mg of oral CBD followed by oral ayahuasca (1 mL/kg) 90 minutes later. Primary outcomes included REFE and empathy tasks (coprimary outcome). Tasks were performed at baseline and 6.5 hours, 1 and 7 days after the interventions. Secondary outcome measures included subjective effects, tolerability, and biochemical assessments.

RESULTS

Significant reductions (all P values <0.05) only in reaction times were observed in the 2 tasks in both groups, without between-group differences. Furthermore, significant reductions in anxiety, sedation, cognitive deterioration, and discomfort were observed in both groups, without between-group differences. Ayahuasca, with or without CBD, was well tolerated, producing mainly nausea and gastrointestinal discomfort. No clinically significant effects were observed on cardiovascular measurements and liver enzymes.

CONCLUSIONS

There was no evidence of interactive effects between ayahuasca and CBD. The safety of separate and concomitant drug intake suggests that both drugs could be applied to clinical populations with anxiety disorders and in further trials with larger samples to confirm findings.

Psychedelic unselfing: self-transcendence and change of values in psychedelic experiences

Psychedelic experiences have been shown to both facilitate (re)connection to one's values and change values, including enhancing aesthetic appreciation, promoting pro-environmental attitudes, and encouraging prosocial behavior. This article presents an empirically informed framework of philosophical psychology to understand how self-transcendence relates to psychedelic value changes. Most of the observed psychedelic value changes are toward the self-transcendent values of Schwartz's value theory. As psychedelics also reliably cause various self-transcendent experiences (STEs), a parsimonious hypothesis is that STEs change values toward self-transcendent values. I argue that STEs indeed can lead to value changes, and discuss the morally relevant process of self-transcendence through Iris Murdoch's concept of "unselfing". I argue that overt egocentric concerns easily bias one's valuations. Unselfing reduces egocentric attributions of salience and enhances non-egocentric attention to the world, widening one's perspective and shifting evaluation toward self-transcendent modes. Values are inherently tied to various evaluative contexts, and unselfing can attune the individual to evaluative contexts and accompanying values beyond the self. Understood this way, psychedelics can provide temporarily enhanced access to self-transcendent values and function as sources of aspiration and value change. However, contextual factors can complicate whether STEs lead to long-term changes in values. The framework is supported by various research strands establishing empirical and conceptual connections between long-term differences in egocentricity, STEs, and self-transcendent values. Furthermore, the link between unselfing and value changes is supported by phenomenological and theoretical analysis of psychedelic experiences, as well as empirical findings on their long-term effects. This article furthers understanding of psychedelic value changes and contributes to discussions on whether value changes are justified, whether they result from cultural context, and whether psychedelics could function as tools of moral neuroenhancement.

Ayahuasca Ritual, Personality and Sociality: Observational Research Conducted in a Substance Use Disorder Rehabilitation Center in Uruguay

The current article presents a mixed qualitative-quantitative observational study of the effect of ayahuasca ritual on subjective experiences and personality traits on participants of a center specialized in the treatment of substance use disorder in Uruguay. When comparing the psychological traits of ayahuasca participants to a control group, quantitative results using the Zuckerman-Kuhlman-Aluja Personality Questionnaire showed statistically significant higher scores in Impulsive Sensation Seeking, Boredom Susceptibility, and Social Warmth scales. Qualitative analysis of ayahuasca experiences resulted in five main categories: emotional experiences (including social emotions such as love and empathy), corporal experiences, spiritual/transcendental experiences, personal experiences, and visions. Last, qualitative descriptions provide support for the importance of social interactions in the phenomenological manifestations of the psychedelic experience. Both quantitative and qualitative results suggest that the combination of social interactions and the pharmacological action of ayahuasca could facilitate the manifestation of social emotions during the ritual, and may contribute to the long-term increase of empathic and social aspects of personality.

The current state of ayahuasca research in animal models: A systematic review

RATIONALE

The psychedelic brew ayahuasca is increasingly being investigated for its therapeutic potential. Animal models are essential to investigate the pharmacological effects of ayahuasca since they can control important factors influencing it, such as the set and setting.

OBJECTIVE

Review and summarise data available on ayahuasca research using animal models.

METHODS

We systematically searched five databases (PubMed, Web of Science, EMBASE, LILACS and PsycInfo) for peer-reviewed studies in English, Portuguese or Spanish published up to July 2022. The search strategy included ayahuasca- and animal model-related terms adapted from the SYRCLE search syntax.

RESULTS

We identified 32 studies investigating ayahuasca effects on toxicological, behavioural and (neuro)biological parameters in rodents, primates and zebrafish. Toxicological results show that ayahuasca is safe at ceremonial-based doses but toxic at high doses. Behavioural results indicate an antidepressant effect and a potential to reduce the reward effects of ethanol and amphetamines, while the anxiety-related outcomes are yet inconclusive; also, ayahuasca can influence locomotor activity, highlighting the importance of controlling the analysis for locomotion when using tasks depending on it. Neurobiological results show that ayahuasca affects brain structures involved in memory, emotion and learning and that other neuropathways, besides the serotonergic action, are important in modulating its effects.

CONCLUSIONS

Studies using animal models indicate that ayahuasca is toxicologically safe in ceremonial-comparable doses and indicates a therapeutic potential for depression and substance use disorder while not supporting an anxiolytic effect. Essential gaps in the ayahuasca field can still be sufficed using animal models.

Psychotherapeutic and neurobiological processes associated with ayahuasca: A proposed model and implications for therapeutic use

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.

Hallucinations and Hallucinogens: Psychopathology or Wisdom?

Hallucinations are currently associated almost exclusively with psychopathological states. While it is evident that hallucinations can indicate psychopathology or neurological disorders, we should remember that hallucinations also commonly occur in people without any signs of psychopathology. A similar case occurs in the case of hallucinogenic drugs, which have been long associated with psychopathology and insanity. However, during the last decades a huge body of research has shown that certain kinds of hallucinations, exerted by hallucinogenic drugs, may serve to improve mental health. We propose that, in light of historical, epidemiological, and scientific research, hallucinations can be better characterized as a common phenomenon associated sometimes with psychopathology but also with functional and even beneficial outcomes. In the last sections of the manuscript, we extend our argument, suggesting that hallucinations can offer a via regia to knowledge of the mind and the world. This radical shift in the cultural interpretation of hallucinations could have several implications for fields such as drug policy, civil law, and psychiatry, as well as for the stigma associated with mental disorders.

Towards an understanding of psychedelic-induced neuroplasticity

Classic psychedelics, such as LSD, psilocybin, and the DMT-containing beverage ayahuasca, show some potential to treat depression, anxiety, and addiction. Importantly, clinical improvements can last for months or years after treatment. It has been theorized that these long-term improvements arise because psychedelics rapidly and lastingly stimulate neuroplasticity. The focus of this review is on answering specific questions about the effects of psychedelics on neuroplasticity. Firstly, we review the evidence that psychedelics promote neuroplasticity and examine the cellular and molecular mechanisms behind the effects of different psychedelics on different aspects of neuroplasticity, including dendritogenesis, synaptogenesis, neurogenesis, and expression of plasticity-related genes (e.g., brain-derived neurotrophic factor and immediate early genes). We then examine where in the brain psychedelics promote neuroplasticity, particularly discussing the prefrontal cortex and hippocampus. We also examine what doses are required to produce this effect (e.g., hallucinogenic doses vs. "microdoses"), and how long purported changes in neuroplasticity last. Finally, we discuss the likely consequences of psychedelics' effects on neuroplasticity for both patients and healthy people, and we identify important research questions that would further scientific understanding of psychedelics' effects on neuroplasticity and its potential clinical applications.

Ayahuasca's therapeutic potential: What we know - and what not

The therapeutic potential of the psychedelic brew ayahuasca has been investigated in preclinical and clinical studies. Currently, the most consistent evidence refers to depression. However, various studies suggest that ayahuasca may comprise therapeutic benefits in other health conditions. This narrative review provides a comprehensive, up-to-date overview of ayahuasca's therapeutic effects in diverse clinical conditions in human (clinical, cross-sectional, observational, and qualitative) and preclinical (animal and in vitro) studies. In addition to summarizing and discussing the most commonly studied conditions, such as depression, anxiety, and substance use disorders (SUD), we also examine less frequently studied psychiatric, neurological, and physical conditions. Moreover, we discuss evidence from epidemiological studies on the impact of regular, long-term ayahuasca use on health and psychosocial outcomes. Overall, evidence for depression and SUD is more consistent, with numerous and diverse studies. However, a growing body of evidence suggests that other conditions equally relevant to public health might be promising targets for ayahuasca's therapeutic effects. This includes preliminary studies indicating potential for grief, eating disorders, posttraumatic stress disorder, personality disorders, Parkinson's and Alzheimer's disease, and severe physical illnesses (e.g., cancer, chronic conditions). Moreover, preliminary evidence in long-term ayahuasca users does not suggest detrimental effects but possible benefits for individual and collective health. In light of the emerging evidence of psychedelic drugs as therapeutic agents, it is essential to further investigate in rigorous designs the therapeutic potential of ayahuasca in conditions other than depression.

Mini-review: The neurobiology of treating substance use disorders with classical psychedelics

The potential of psychedelics to persistently treat substance use disorders is known since the 1960s. However, the biological mechanisms responsible for their therapeutic effects have not yet been fully elucidated. While it is known that serotonergic hallucinogens induce changes in gene expression and neuroplasticity, particularly in prefrontal regions, theories on how specifically this counteracts the alterations that occur in neuronal circuitry throughout the course of addiction are largely unknown. This narrative mini-review endeavors to synthesize well-established knowledge from addiction research with findings and theories regarding the neurobiological effects of psychedelics to give an overview of the potential mechanisms that underlie the treatment of substance use disorders with classical hallucinogenic compounds and point out gaps in the current understanding.

Prophylactic action of ayahuasca in a non-human primate model of depressive-like behavior

Observational studies of long-term users of ayahuasca, an Amazonian psychedelic brew, suggest an increase in resilience via improvements in emotion and cognition. Ayahuasca has also demonstrated clinical antidepressant effects in human and animal studies; however, its potential prophylactic action in depression has not been previously studied. Therefore, this experimental study sought to evaluate the potential prophylactic effects of repeated and long-term ayahuasca use, via the modulation of resilience, in a non-human primate animal model, Callithrix jacchus, subjected to a protocol for induction of depressive-like behavior. For the formation of the study groups, some juvenile marmosets were kept in their family groups (GF = 7), while for the two experimental groups, the animals were removed from the family and kept socially isolated. Then, part of the isolated animals made up the group in which ayahuasca was administered (AG, n = 6), while for others, no intervention was made (IG, n = 5). AG animals took ayahuasca (1.67 mL/300g body weight) at weeks 4 (before isolation), 8, and 12 (during isolation) of the study. More adaptive stress response was observed for the AG when compared to the IG. The AG showed higher cortisol reactivity and fecal cortisol levels than IG, while both measures were similar to FG. Moreover, AG animals showed no signs of anhedonia and no increase in chronic stress-related behaviors, which were expressed by the IG. Thus, ayahuasca seems to promote the expression of resilient responses, indicating a prophylactic action, buffering the emergence of depressive-like behaviors and cortisol alterations associated with major depression. These results are encouraging for further research on the prophylactic use of psychedelics to prevent psychopathologies associated with chronic stress.

Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant

Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic N,N-dimethyltryptamine (DMT), which is thought to be the main psychoactive alkaloid present in the brew. The latter serves as a source for β-carbolines, known for their monoamine oxidase-inhibiting (MAOI) properties. Recent preliminary research has provided encouraging results investigating ayahuasca’s therapeutic potential, especially regarding its antidepressant effects. On a molecular level, pre-clinical and clinical evidence points to a complex pharmacological profile conveyed by the brew, including modulation of serotoninergic, glutamatergic, dopaminergic, and endocannabinoid systems. Its substances also interact with the vesicular monoamine transporter (VMAT), trace amine-associated receptor 1 (TAAR1), and sigma-1 receptors. Furthermore, ayahuasca’s components also seem to modulate levels of inflammatory and neurotrophic factors beneficially. On a biological level, this translates into neuroprotective and neuroplastic effects. Here we review the current knowledge regarding these molecular interactions and how they relate to the possible antidepressant effects ayahuasca seems to produce.

Beyond the Psychoactive Effects of Ayahuasca: Cultural and Pharmacological Relevance of Its Emetic and Purging Properties

The herbal preparation ayahuasca has been an important part of ritual and healing practices, deployed to access invisible worlds in several indigenous groups in the Amazon basin and among mestizo populations of South America. The preparation is usually known to be composed of two main plants, Banisteriopsis caapi and Psychotria viridis, which produce both hallucinogenic and potent purging and emetic effects; currently, these are considered its major pharmacological activities. In recent decades, the psychoactive and visionary effect of ayahuasca has been highly sought after by the shamanic tourism community, which led to the popularization of ayahuasca use globally and to a cultural distancing from its traditional cosmological meanings, including that of purging and emesis. Further, the field of ethnobotany and ethnopharmacology has also produced relatively limited data linking the phytochemical diversity of ayahuasca with the different degrees of its purging and emetic versus psychoactive effects. Similarly, scientific interest has also principally addressed the psychological and mental health effects of ayahuasca, overlooking the cultural and pharmacological importance of the purging and emetic activity. The aim of this review is therefore to shed light on the understudied purging and emetic effect of ayahuasca herbal preparation. It firstly focuses on reviewing the cultural relevance of emesis and purging in the context of Amazonian traditions. Secondly, on the basis of the main known phytochemicals described in the ayahuasca formula, a comprehensive pharmacological evaluation of their emetic and purging properties is presented.

Changes in mental health, wellbeing and personality following ayahuasca consumption: Results of a naturalistic longitudinal study

Background: Naturalistic and placebo-controlled studies suggest ayahuasca, a potent psychedelic beverage originating from Indigenous Amazonian tradition, may improve mental health, alter personality structure, and reduce alcohol and drug intake. To better understand ayahuasca’s therapeutic potential and to identify factors that influence therapeutic efficacy, we conducted a naturalistic, longitudinal study of facilitated ayahuasca consumption in naïve participants using a comprehensive battery of self-report questionnaires.

Materials and Methods: Ayahuasca naive individuals registering for ayahuasca ceremonies were asked to complete a range of validated questionnaires assessing mental health, alcohol/cannabis use, relationships, personality, and connection to self and spirituality, prior to and 1 month after attending an ayahuasca ceremony. Data for two mental health measures (the DASS-21 and PANAS) and acute subjective effects via the MEQ-30 were also assessed 7 days post-ceremony. Repeated measures ANOVA were used to examine pre-to-post changes, and Pearson correlations explored predictors of improvement in outcomes.

Results: Fifty-three attendees (32 women, 21 men) completed pre and post ayahuasca assessments with 55.6% of the sample reporting a complete mystical experience based on the MEQ-30. One-month post-ayahuasca, significant reductions were identified in depression, anxiety, stress, alcohol and cannabis use, body dissociation, accepting external influence, self-alienation, impulsivity, and negative affect/emotionality. Significant increases were identified in positive mood, self-efficacy, authentic living, extraversion, agreeableness, open-mindedness, spirituality, and satisfaction with relationships. While facets of the mystical experience held little predictive validity on outcome measures, baseline traits, particularly high negative emotionality and body dissociation, and low sense of self-efficacy, robustly predicted improvements in mental health and alcohol/cannabis use, and alterations in personality structure which are linked to better mental health.

Discussion: This study suggests facilitated ayahuasca consumption in naïve participants may precipitate wide-ranging improvements in mental health, relationships, personality structure, and alcohol use. Associations between baseline traits and therapeutic improvements mark an important first step toward personalized, precision-based medicine and warrant randomized controlled trials to confirm and elaborate on these findings.

Contribution Statement: Longitudinal, observational studies and randomized clinical control trials suggest ayahuasca may exert therapeutic effects on mental health and alcohol/cannabis use, and alter personality structure. However, it is unclear if improvements are diagnosis-specific and factors that predict therapeutic gains have yet to be extensively elucidated. This longitudinal, observational study examined the effects of facilitated ayahuasca consumption in naive participants on mental health, alcohol and substance use/abuse, personality traits, relationships, and connection to self and spirituality. We found wide-ranging improvements 1-month post-treatment across these domains, and identified baseline traits which predict pre-to-post changes on primary outcome measures. Improvements were not diagnostic-specific, suggesting ayahuasca may be generally efficacious. Personality traits, body dissociation, and self-efficacy were strong predictors of therapeutic improvements, marking an important first step toward personalized, precision-based medicine. Randomized controlled trials are warranted to confirm and elaborate on these findings.

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

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

Naturalistic use of psychedelics is related to emotional reactivity and self-consciousness: The mediating role of ego-dissolution and mystical experiences

BACKGROUND

Psychedelics are able to acutely alter emotional reactivity and self-consciousness. However, whether the regular naturalistic use of psychedelics can be linked to more persistent trait-level changes in these domains remains an open question.

AIM

To test the hypotheses that (1) using psychedelics is related to higher positive and lower negative emotional reactivity; and (2) an adaptive pattern of self-consciousness, including diminished public self-consciousness and rumination, and increased reflection and self-awareness; and (3) these relations are mediated by the intensity of past ego-dissolution and mystical experiences.

METHOD

An online survey including questions about the history of psychoactive substance use; questionnaires measuring trait levels of emotional reactivity and self-consciousness; questionnaires for retrospective assessment of ego-dissolution and mystical experiences. Data collected from 2516 participants (1661 psychedelics users) were analyzed using robust linear regression and mediation analysis.

RESULTS

A higher number of lifetime uses of psychedelics predicted greater positive and lower negative emotional reactivity; also, in the domain of self-consciousness, it predicted greater reflection and internal state awareness, and reduced rumination tendency and public self-consciousness. Finally, the intensity of past mystical and ego-dissolution experiences mediated almost all the observed relationships between the lifetime number of psychedelics uses and psychological variables.

CONCLUSIONS

Lifetime psychedelics use predicts an adaptive pattern of trait-level emotional reactivity and self-consciousness. Ego-dissolution and mystical experiences are essential in understanding the long-lasting psychological effects of psychedelics use. Our findings might potentially explain previous observations of increased well-being in psychedelics users.

Three Naturally-Occurring Psychedelics and Their Significance in the Treatment of Mental Health Disorders

Classical psychedelics represent a family of psychoactive substances with structural similarities to serotonin and affinity for serotonin receptors. A growing number of studies have found that psychedelics can be effective in treating various psychiatric conditions, including post-traumatic stress disorder, major depressive disorder, anxiety, and substance use disorders. Mental health disorders are extremely prevalent in the general population constituting a major problem for the public health. There are a wide variety of interventions for mental health disorders, including pharmacological therapies and psychotherapies, however, treatment resistance still remains a particular challenge in this field, and relapse rates are also quite high. In recent years, psychedelics have become one of the promising new tools for the treatment of mental health disorders. In this review, we will discuss the three classic serotonergic naturally occurring psychedelics, psilocybin, ibogaine, and N, N-dimethyltryptamine, focusing on their pharmacological properties and clinical potential. The purpose of this article is to provide a focused review of the most relevant research into the therapeutic potential of these substances and their possible integration as alternative or adjuvant options to existing pharmacological and psychological therapies.

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.

Nootropic effects of LSD: Behavioral, molecular and computational evidence

The therapeutic use of classical psychedelic substances such as d-lysergic acid diethylamide (LSD) surged in recent years. Studies in rodents suggest that these effects are produced by increased neural plasticity, including stimulation of the mTOR pathway, a key regulator of metabolism, plasticity, and aging. Could psychedelic-induced neural plasticity be harnessed to enhance cognition? Here we show that LSD treatment enhanced performance in a novel object recognition task in rats, and in a visuo-spatial memory task in humans. A proteomic analysis of human brain organoids showed that LSD affected metabolic pathways associated with neural plasticity, including mTOR. To gain insight into the relation of neural plasticity, aging and LSD-induced cognitive gains, we emulated the experiments in rats and humans with a neural network model of a cortico-hippocampal circuit. Using the baseline strength of plasticity as a proxy for age and assuming an increase in plasticity strength related to LSD dose, the simulations provided a good fit for the experimental data. Altogether, the results suggest that LSD has nootropic effects.

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.

Ayahuasca and Public Health II: Health Status in a Large Sample of Ayahuasca-Ceremony Participants in the Netherlands

Ayahuasca is a plant decoction in traditional Amazonian medicine. Its ritual use has been internationalized, leading to policy challenges that countries should address. This study evaluates the impact of regular ayahuasca ceremony participation on health by assessing the health status of 377 participants in ayahuasca ceremonies in the Netherlands using validated health indicators. A questionnaire was developed and administered to study participants. The questionnaire included several health indicators with public health relevance (e.g., BMI, diet, physical activity) and psychometrically validated questionnaires (ELS and COPE-easy). The data retrieved through health indicators was compared to normative Dutch data. Participants (50.1% women) were mostly Dutch (84.6%) with a mean age of 48.8 years (SD = 11.6). Compared to normative Dutch data, regular participants in ayahuasca ceremonies showed better general well-being, fewer chronic or lifestyle-related diseases, more physical activity, and a more balanced diet. Participants also used less alcohol during the COVID-19 pandemic, and although they used more illegal drugs than the general population, they did not report associated harms. Our findings suggest that regular participation in ayahuasca ceremonies is not linked to relevant health harms. This data could help drug policymakers to develop and implement evidence-based public policies.

N,N-dimethyltryptamine and Amazonian ayahuasca plant medicine

OBJECTIVE

Reports have indicated possible uses of ayahuasca for the treatment of conditions including depression, addictions, post-traumatic stress disorder, anxiety and specific psychoneuroendocrine immune system pathologies. The article assesses potential ayahuasca and N,N-dimethyltryptamine (DMT) integration with contemporary healthcare. The review also seeks to provide a summary of selected literature regarding the mechanisms of action of DMT and ayahuasca; and assess to what extent the state of research can explain reports of unusual phenomenology.

DESIGN

A narrative review.

RESULTS

Compounds in ayahuasca have been found to bind to serotonergic receptors, glutaminergic receptors, sigma-1 receptors, trace amine-associated receptors, and modulate BDNF expression and the dopaminergic system. Subjective effects are associated with increased delta and theta oscillations in amygdala and hippocampal regions, decreased alpha wave activity in the default mode network, and stimulations of vision-related brain regions particularly in the visual association cortex. Both biological processes and field of consciousness models have been proposed to explain subjective effects of DMT and ayahuasca, however, the evidence supporting the proposed models is not sufficient to make confident conclusions. Ayahuasca plant medicine and DMT represent potentially novel treatment modalities.

CONCLUSIONS

Further research is required to clarify the mechanisms of action and develop treatments which can be made available to the general public. Integration between healthcare research institutions and reputable practitioners in the Amazon is recommended.

LSD, afterglow and hangover: Increased episodic memory and verbal fluency, decreased cognitive flexibility

Psychedelics acutely impair cognitive functions, but these impairments decline with growing experiences with psychedelics and microdoses may even exert opposing effects. Given the recent evidence that psychedelics induce neuroplasticity, this explorative study aimed at investigating the potential of psychedelics to sub-acutely change cognition. For this, we applied a randomized, double-blind, placebo-controlled, crossover study with 24 healthy volunteers receiving 50 μg lysergic acid diethylamide (LSD) or an inactive placebo. Sub-acute changes in cognition were measured 24 h after dosing, including memory (Rey-Osterrieth Complex Figure, ROCF; 2D Object-Location Memory Task, OLMT; Rey Auditory-Verbal Learning Test, RAVLT), verbal fluency (phonological; semantic; switch), design fluency (basic; filter; switch), cognitive flexibility (Wisconsin Card Sorting Test, WCST), sustained and switching attention (Trail Making Test, TMT), inhibitory control (Stroop Task) and perceptual reasoning (Block Design Test, BDT). The results show that when compared to placebo and corrected for Body Mass Index (BMI) and abstinence period from psychedelics, LSD sub-acutely improved visuospatial memory (ROCF immediate recall points and percentage, OLMT consolidation percentage) and phonological verbal fluency and impaired cognitive flexibility (WCST: fewer categories achieved; more perseveration, errors and conceptual level responses). In conclusion, the low dose of LSD moderately induced both "afterglow" and "hangover". The improvements in visuospatial memory and phonological fluency suggest that LSD-assisted therapy should be explored as a novel treatment perspective in conditions involving memory and language declines such as brain injury, stroke or dementia.

Teacher plants - Indigenous Peruvian-Amazonian dietary practices as a method for using psychoactives

ETHNOPHARMACOLOGICAL RELEVANCE

Indigenous groups of the Amazon have developed intricate methods for the application of psychoactives, among which particularly the dieta or diet method of Peruvian-Amazonian traditional medicine stands out. It is a retreat-like intervention involving lengthy periods of social, behavioural, and alimentary restrictions, while ingesting specially prepared plant substances. The interplay of the dietary conditions and plants ingested sensitizes the dieter to receive healing, strength, guidance, and knowledge. From a clinical scientific point of view, the method has remained largely underexplored, but seems more pertinent than ever given the increasing interest in Amazonian psychoactive preparations including ayahuasca (Banisteriopsis caapi) and the burgeoning field of psychedelic-assisted therapies in general.

AIM OF THE STUDY

This study offers a descriptive account and emic interpretation of the Peruvian-Amazonian dieta. More specifically we document in detail the procedure, its context and purpose of application, effects, modes of action, adverse effects, and risks, from the perspectives of a sample of Peruvian traditional healers. The Peruvian-Amazonian dieta is a multi-purpose method for making use of medicinal plants, many of which (but not all), are psychoactive; the current work especially focuses on its therapeutic applications in conjunction with psychoactives.

METHODS

We interviewed 16 healers working in the Ucayali, San Martín, and Loreto provinces of Peru using a semi-structured interview approach. Interviews were audio-recorded and transcribed verbatim. The extensive data derived from these interviews were analysed by means of computer-assisted manifest qualitative content analysis using a theory-advancing approach. Over 500 coded text segments were categorized, resulting in 7 main theme clusters and corresponding sub-themes.

RESULTS

The interviewed healers described a complex intervention with multifaceted applications (treatment, prevention, training) and effects in various domains (body, mind, spirit, energy). The process was portrayed as transformative, with benefits attributed to the effects of the so-called teacher plants in conjunction with the diet's conditions, along with the skill of the healer guiding the intervention. Further, a detailed risk assessment revealed sophisticated safety measures and tools designed to address adverse responses. The importance of adequate training of the healer that administers the diet was particularly highlighted in this context.

CONCLUSIONS

The dieta is a central therapeutic concept and tool in Peruvian-Amazonian traditional medicine and a unique method for using psychoactive plants. Multidisciplinary health research that includes traditional treatment methods from Indigenous cultures, Amazonian and other, should not be neglected in the current global interest in psychedelic therapies; such research may in the long-term contribute to a more inclusive psychedelic research paradigm as well as healthcare practice in countries where rich traditional healing systems exist, and perhaps beyond. It may also contribute to the recognition of the Indigenous healers as not only historical forerunners, but also current leading experts in psychedelic medicine.

Ayahuasca, a potentially rapid acting antidepressant: focus on safety and tolerability

INTRODUCTION

Ayahuasca is a psychedelic brew originally used by indigenous tribes from the Amazon Rainforest and in religious rituals. Pre-clinical and observational studies have demonstrated its possible potential as an antidepressant, and open and placebo-controlled clinical trials corroborated these results. For it to become an approved treatment for depression, its safety and tolerability need to be assessed and documented.

AREAS COVERED

We have gathered data regarding occurrence of adverse events (AEs) in all reported randomized, placebo-controlled trials with healthy and clinical populations involving ayahuasca administration (n = 108 ayahuasca administrations). We systematically categorized these results, recorded their prevalence and discussed the possible mechanisms related to their emergence.

EXPERT OPINION

: There were no reports of serious AEs, indicating a relative safety of ayahuasca administration in controlled settings. Most common AEs related to ayahuasca administration included nausea, vomiting, headaches and transient increases in cardiovascular measurements. Ayahuasca research is still in its infancy, especially concerning the absence of large and robust clinical trials to verify its antidepressant effects. Dose standardization, legal prohibition of the possession of its alkaloids and how traditional communities will be compensated if ayahuasca becomes an approved medicine are the biggest obstacles to overcome for its future use in the therapeutic context.

Adverse effects of psychedelics: From anecdotes and misinformation to systematic science

BACKGROUND

Despite an increasing body of research highlighting their efficacy to treat a broad range of medical conditions, psychedelic drugs remain a controversial issue among the public and politicians, tainted by previous stigmatisation and perceptions of risk and danger.

OBJECTIVE

This narrative review examines the evidence for potential harms of the classic psychedelics by separating anecdotes and misinformation from systematic research.

METHODS

Taking a high-level perspective, we address both psychological and psychiatric risks, such as abuse liability and potential for dependence, as well as medical harms, including toxicity and overdose. We explore the evidence base for these adverse effects to elucidate which of these harms are based largely on anecdotes versus those that stand up to current scientific scrutiny.

RESULTS

Our review shows that medical risks are often minimal, and that many - albeit not all - of the persistent negative perceptions of psychological risks are unsupported by the currently available scientific evidence, with the majority of reported adverse effects not being observed in a regulated and/or medical context.

CONCLUSIONS

This highlights the importance for clinicians and therapists to keep to the highest safety and ethical standards. It is imperative not to be overzealous and to ensure balanced media reporting to avoid future controversies, so that much needed research can continue.

Ayahuasca, a psychedelic beverage, modulates neuroplasticity induced by ethanol in mice

Alcohol use disorder needs more effective treatments because relapse rates remain high. Psychedelics, such as ayahuasca, have been used to treat substance use disorders. Our study aimed to evaluate the effects of ayahuasca on ethanol-induced behavioral sensitization (EIBS). Swiss mice received 2.2 g/kg ethanol or saline IP injections every other day across nine days (D1, D3, D5, D7, and D9), and locomotor activity was evaluated 10 min after each injection. Then, animals were treated daily with ayahuasca (corresponding to 1.76 mg/kg of N,N-dimethyltryptamine, DMT) or water by oral gavage for eight consecutive days. On the seventh day, mice were evaluated in the elevated plus maze. Then, mice were challenged with a single dose of ethanol to measure their locomotor activity. Dopamine receptors, serotonin receptors, dynorphin, and prodynorphin levels were quantified in the striatum and hippocampus by blot analysis. Repeated ethanol administration resulted in EIBS. However, those animals treated with ayahuasca had an attenuated EIBS. Moreover, ayahuasca reduced the anxiogenic response to ethanol withdrawal and prevented the ethanol-induced changes on 5-HT1a receptor and prodynorphin levels in the hippocampus and reduced ethanol effects in the dynorphin/prodynorphin ratio levels in the striatum. These results suggest a potential application of ayahuasca to modulate the neuroplastic changes induced by ethanol.

Preliminary evidence of links between ayahuasca use and the corpus callosum

BACKGROUND

Recent research suggests that ayahuasca and its alkaloid-containing ingredients may be helpful in the treatment and prevention of certain movement and neurodegenerative disorders. However, such research is still in its infancy and more studies in normative samples seem necessary to explore effects of ayahuasca on clinically relevant brain structures, such as the corpus callosum.

AIMS

The purpose of the present study was to investigate links between ayahuasca use and callosal structure in a normative sample.

METHODS

Using structural imaging data from 22 ayahuasca users and 22 matched controls we compared the thickness of the corpus callosum between both groups at 100 equidistant points across the entire midsagittal surface. In addition, we investigated point-wise correlations between callosal thickness and the number of past ayahuasca sessions.

RESULTS

The corpus callosum was significantly thicker within the isthmus in the ayahuasca group than in the control group. There was also a significant positive correlation between callosal thickness and the number of past ayahuasca sessions within the rostral body, albeit none of these effects survived corrections for multiple comparisons. No region was significantly thicker in the control than in the ayahuasca group, and no callosal region was negatively linked to ayahuasca use, even at uncorrected significance thresholds.

CONCLUSION

This study provides preliminary evidence of links between ayahuasca use and the corpus callosum. However, future studies need to replicate these findings, preferably using larger sample sizes and ideally also utilizing longitudinal research designs, to draw any practical conclusion and offer implications for follow-up clinical research.

Therapeutic effect of an ayahuasca analogue in clinically depressed patients: a longitudinal observational study

RATIONALE

Studies have suggested mental health improvements following the use of the psychotropic plant concoction ayahuasca in non-clinical and clinical samples.

OBJECTIVES

The present observational study assessed depressive symptomatology in 20 clinically depressed patients (symptom score > 13 on the Beck's Depression Inventory) before attendance of an ayahuasca ceremony and 1 month and 1 year after. Secondary measures included ratings of altered states of consciousness and ego dissolution during the ayahuasca ceremony as well as global measures of mindfulness, satisfaction with life, depression, anxiety, and stress.

RESULTS

Twenty participants completed baseline and 1-day follow-up, 19 completed measures at 1-month follow-up, and 17 completed measures at 1-year follow-up. BDI scores reduced from baseline (M = 22.7) to all post-ceremony measures (Ms 11.45, 12.89, and 8.88, for 1-day, 1-month, and 1-year follow-up, respectively). After 1 day, 12/20 participants were in remission (BDI < 13). Remission rates after 1 month and 1 year were 13/19 and 12/17, respectively. Three participants remained mildly depressed (BDI 14-19) at the 1-month and 1-year follow-up. Two participants did not respond and remained at a moderate/severe level of depression at 1-year follow-up. Reductions on the secondary mental health measures and increases in mindfulness and satisfaction with life were found up to 1 year post-ceremony. Improvements in clinical depression and mental health correlated with levels of experienced ego dissolution and oceanic boundlessness during the ceremony up to 1 month after the ceremony. Engagement in additional mental health treatments or use of another psychedelic during study participation may have contributed to improved mental health ratings at 1-year follow-up.

CONCLUSION

Ayahuasca produces long-term mental health improvements in clinically depressed patients, which highlights its therapeutic potential.

Decreases in State and Trait Anxiety Post-psilocybin: A Naturalistic, Observational Study Among Retreat Attendees

Anxiety disorders are the most common type of psychiatric disorders among Western countries. Evidence-based treatment modalities including pharmacological and cognitive-behavioral therapy result in deficient treatment responses. Historical and recent research suggests psychedelic drugs may be efficacious in alleviating anxiety-related symptoms among healthy and clinical populations. The main aim of the present study was investigation of the effects of psilocybin-containing truffles, when taken in a supportive group setting, on ratings of state and trait anxiety across self-reported healthy volunteers. Attendees of psilocybin ceremonies were asked to complete a test battery at three separate occasions: before the ceremony (baseline), the morning after, and 1 week after the ceremony. The test battery included questionnaires assessing state and trait anxiety (State-Trait Anxiety Inventory), mindfulness capacities (Five Facet Mindfulness Questionnaire), and personality (Big Five Inventory). Additionally, the psychedelic experience was quantified with the Persisting Effects Questionnaire and the Ego Dissolution Inventory. The total amount of psilocybin-containing truffles consumed by each participant was recorded, and a sample of the truffles was analyzed to determine psilocin concentrations. Fifty-two attendees (males = 25; females = 25; others = 2) completed parts of the baseline assessment, 46 (males = 21; females = 24; others = 1) completed assessments the morning after the ceremony, and 23 (males = 10; females = 13) completed assessments at the 1-week follow-up. Average psilocin consumption across individuals was 27.1 mg. The morning after the ceremony, we observed medium reductions in anxiety measures (both state and trait) compared to baseline ( d ¯ = 6.4; p < 0.001 and d ¯ = 6; p = 0.014, respectively), which persisted over a 1-week period post-ceremony ( d ¯ = 6.7; p = 0.001 and d ¯ = 8.6; p = 0.004, respectively). At 1 week post-ceremony, the non-judging facet of the mindfulness scale was increased ( d ¯ = 1.5; p = 0.03), while the personality trait neuroticism decreased ( d ¯ = 5.2; p = 0.005), when compared to baseline. Additionally, we found ratings of ego dissolution (mean: 59.7, SD: 28.3) and changes in neuroticism to be the strongest predictors of reductions in state and trait anxiety, respectively. In sum, results suggest rapid and persisting (up to 1 week) anxiolytic effects in individuals with sub-clinical anxiety symptoms, which are related to the acute experience of ego dissolution, as well as lasting changes in trait neuroticism. Results also add support to the feasibility and potential efficacy of group sessions with psychedelics. To understand whether these effects extend to wider populations suffering from heightened anxiety, and the mechanisms involved, further experimental research is needed.

3,4-Methylenedioxy methamphetamine, synthetic cathinones and psychedelics: From recreational to novel psychotherapeutic drugs

The utility of classical drugs used to treat psychiatric disorders (e.g., antidepressants, anxiolytics) is often limited by issues of lack of efficacy, delayed onset of action or side effects. Psychoactive substances have a long history of being used as tools to alter consciousness and as a gateway to approach the unknown and the divinities. These substances were initially obtained from plants and animals and more recently by chemical synthesis, and its consumption evolved toward a more recreational use, leading to drug abuse-related disorders, trafficking, and subsequent banning by the authorities. However, these substances, by modulation of certain neurochemical pathways, have been proven to have a beneficial effect on some psychiatric disorders. This evidence obtained under medically controlled conditions and often associated with psychotherapy, makes these substances an alternative to conventional medicines, to which in many cases the patient does not respond properly. Such disorders include post-traumatic stress disease and treatment-resistant depression, for which classical drugs such as MDMA, ketamine, psilocybin and LSD, among others, have already been clinically tested, reporting successful outcomes. The irruption of new psychoactive substances (NPS), especially during the last decade and despite their recreational and illicit uses, has enlarged the library of substances with potential utility on these disorders. In fact, many of them were synthetized with therapeutic purposes and were withdrawn for concrete reasons (e.g., adverse effects, improper pharmacological profile). In this review we focus on the basis, existing evidence and possible use of synthetic cathinones and psychedelics (specially tryptamines) for the treatment of mental illnesses and the properties that should be found in NPS to obtain new therapeutic compounds.

Adverse effects of ayahuasca: Results from the Global Ayahuasca Survey

INTRODUCTION

Ayahuasca is a plant-based decoction native to Amazonia, where it has a long history of use in traditional medicine. Contemporary ritual use of ayahuasca has been expanding throughout the world for mental health purposes, and for spiritual and personal growth. Although researchers have been conducting clinical trials and observational studies reporting medical and psychological benefits, most of these do not report ayahuasca's immediate or medium-term adverse effects, so these are underrepresented in the literature. With the expansion of ayahuasca ceremonies from their traditional contexts to countries around the world, there is an important public health question regarding the risk/benefit balance of its use.

METHODS

We used data from an online Global Ayahuasca Survey (n = 10,836) collected between 2017 and 2019 involving participants from more than 50 countries. Principal component analysis was performed to assess group effects. Logistic regression analysis was performed to test for adverse effects associated with history of ayahuasca use, clinical, context of use and spiritual effect variables.

RESULTS

Acute physical health adverse effects (primarily vomiting) were reported by 69.9% of the sample, with 2.3% reporting the need for subsequent medical attention. Adverse mental health effects in the weeks or months following consumption were reported by 55.9% of the sample, however, around 88% considered such mental health effects as part of a positive process of growth or integration. Around 12% sought professional support for these effects. Physical adverse effects were related to older age at initial use of ayahuasca, having a physical health condition, higher lifetime and last year ayahuasca use, having a previous substance use disorder diagnosis, and taking ayahuasca in a non-supervised context. Mental health adverse effects were positively associated with anxiety disorders; physical health conditions; and the strength of the acute spiritual experience; and negatively associated with consumption in religious settings.

CONCLUSIONS

While there is a high rate of adverse physical effects and challenging psychological effects from using ayahuasca, they are not generally severe, and most ayahuasca ceremony attendees continue to attend ceremonies, suggesting they perceive the benefits as outweighing any adverse effects. Knowing what variables might predict eventual adverse effects may serve in screening of, or providing additional support for, vulnerable subjects. Improved understanding of the ayahuasca risk/benefit balance can also assist policy makers in decisions regarding potential regulation and public health responses.

How to account for hallucinations in the interpretation of the antidepressant effects of psychedelics: a translational framework

RATIONALE

Recent trials with psychedelics in major depressive disorder and treatment-resistant depression showed remarkable improvements in depressive symptoms that can last for up to several months after even a single administration. The lack of an appropriate placebo control group-as patients are often able to discriminate the subjective effects of the drug-and an incomplete understanding of the role of the hallucinogenic and mystical experience, hampers the interpretation of these therapeutic effects.

OBJECTIVES

To control for these factors, we developed a translational framework based on establishing pharmacokinetic/pharmacodynamic (PK/PD) relationships in rodents and humans for hallucinogenic (i.e., discriminative stimulus effects in rodents and humans; head twitch responses in rodents; questionnaires in humans) and therapeutic effects. For the latter, we selected the pattern separation and attentional set-shifting tasks as measures for cognitive flexibility because of their high translational value. We predict that these PK/PD analyses will lead to a more objective evaluation of improvements in patients compared to relying only on the currently used self-reported questionnaires. We hypothesize that-if the role of the hallucinogenic experience is not central in the antidepressant effects of psychedelics-the ED₅₀'s for the therapeutic effects will be significantly lower than for the hallucinogenic and mystical effects.

CONCLUSION

Our framework will help to inform future studies that aim at the elucidation of the mechanism(s) of action of psychedelics in depression, and the role of the acute subjective and/or hallucinogenic experience in their effects.

Analysis of recreational psychedelic substance use experiences classified by substance

RATIONALE AND OBJECTIVES

Differences among psychedelic substances regarding their subjective experiences are clinically and scientifically interesting. Quantitative linguistic analysis is a powerful tool to examine such differences. This study compared five psychedelic substance report groups and a non-psychedelic report group on quantitative linguistic markers of psychological states and processes derived from recreational use-based online experience reports.

METHODS

Using 2947 publicly available online reports, we compared Ayahuasca and N,N-dimethyltryptamine (DMT, analyzed together), ketamine, lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), psilocybin (mushroom), and antidepressant drug use experiences. We examined word frequencies related to various psychological states and processes and semantic proximity to psychedelic and mystical experience scales.

RESULTS

Linguistic markers of psychological function indicated distinct effect profiles. For example, MDMA experience reports featured an emotionally intensifying profile accompanied by many cognitive process words and dynamic-personal language. In contrast, Ayahuasca and DMT experience reports involved relatively little emotional language, few cognitive process words, increased analytical thinking-associated language, and the most semantic similarity with psychedelic and mystical experience descriptions. LSD, psilocybin mushroom, and ketamine reports showed only small differences on the emotion-, analytical thinking-, psychedelic, and mystical experience-related language outcomes. Antidepressant reports featured more negative emotional and cognitive process-related words, fewer positive emotional and analytical thinking-related words, and were generally not similar to mystical and psychedelic language.

CONCLUSION

This article addresses an existing research gap regarding the comparison of different psychedelic drugs on linguistic profiles of psychological states, processes, and experiences. The large sample of experience reports involving multiple psychedelic drugs provides valuable information that would otherwise be difficult to obtain. The results could inform experimental research into psychedelic drug effects in healthy populations and clinical trials for psychedelic treatments of psychiatric problems.