N,N-dimethyltryptamine and Amazonian ayahuasca plant medicine

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

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

Benefits and Challenges of Ultra-Fast, Short-Acting Psychedelics in the Treatment of Depression

Unlike classical antidepressants, psychedelics such as psilocybin have been shown to induce a rapid antidepressant response. In the wake of this development, interest has emerged in ultra-fast, short-acting psychedelics such as 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and N,N-dimethyltryptamine (DMT) with the expectation that these can produce rapid antidepressant effects following an intense but brief psychedelic intervention. The current paper reviews the clinical pharmacology of 5-MeO-DMT and DMT and their potential benefits and challenges in the treatment of depression. Both compounds display affinities for a variety of monoamine receptors and transporters, but mostly so for serotonergic (5HT) receptors, including 5HT1A and 5HT2A. Early clinical trials in small samples have shown that short interventions (15-30 min) with 5-MeO-DMT and DMT are safe and well tolerated and can induce marked improvement in symptoms of depression within 24 hours that sustain for at least 1 week. Data on long-term efficacy are currently scarce but do suggest a prolongation of the treatment response. Potential benefits of these treatments include flexible, single day dosing regimens, achievement of treatment efficacy independent from integrative therapy, and ease of clinical implementation. Future challenges include establishing the duration of the antidepressant effect and strategies on how to sustain the antidepressant response, optimization of treatment delivery parameters, and a mechanistic understanding of the clinical response. Acceptance of ultra-fast, short-acting psychedelics will depend on future randomized, placebo-controlled trials with a focus on replication, duration and maintenance of antidepressant efficacy in large patient samples.

Associations Between Ayahuasca Use in Naturalistic Settings and Mental Health and Wellbeing Outcomes: Analysis of a Large Global Dataset

Emerging evidence indicates that ayahuasca consumption may have beneficial mental health effects. This study undertakes the largest analysis to date of associations between naturalistic ayahuasca use and current mental health status via an online cross-sectional survey. The sample included 7,576 participants (average age 41, 47% female) who had consumed ayahuasca in religious, traditional, or non-traditional settings in over 50 countries. Bivariate analysis, multivariate linear regressions and generalized structural equation modeling were used to explore associations between ayahuasca use variables, current mental health (K10, SF-12 MCS), and psychological well-being change (PWG). The number of ayahuasca uses was found to be positively associated with current mental health status (all measures), and this remained highly significant in multivariate models, with little evidence of associations diminishing over time. Variables such as the strength of the mystical experience, self-insights, and community/social variables were also positively associated with current mental health and PWG, while acute extreme fear and integration difficulties were negatively associated. Findings suggest that naturalistic ayahuasca use is associated with better current mental health status and enhanced psychological wellbeing for individuals with and without a history of mental illness, independent of community effects, with certain variables contributing positively or negatively to these effects.

Drug-induced psychosis following use of Ayahuasca: a presentation to forensic psychiatric services

Ayahuasca is a plant-based psychoactive decoction, traditionally used by indigenous Amazonian peoples, which commonly contains the hallucinogen N,N-dimethyltryptamine (DMT). There is now growing interest across the Western world in psychedelics including Ayahuasca.This case describes a previously well male with no risk factors for adverse psychiatric outcomes or forensic history. Following controlled Ayahuasca use, he developed an enduring psychotic episode, during which he significantly assaulted a relative and was admitted to a forensic psychiatric unit. He was treated with the antipsychotic aripiprazole, and his psychotic symptoms abated. 18 months following his admission, recovery has been sustained.Previous case reports have described psychosis following Ayahuasca ingestion, but typically of short duration in patients with a personal or family history of psychiatric illness, or in those taking other substances. With the growing use of Ayahuasca, it is important to highlight that adverse effects may include more prolonged psychotic symptoms and the risk of psychotically mediated violence.

Ayahuasca for the treatment of alcohol use disorder

For decades, psychedelics have been investigated for the treatment of psychiatric disorders. Specifically, evidence suggests that psychedelics may have therapeutic potential for the treatment of alcohol use disorder. Several studies with classic psychedelics, including LSD and psilocybin, show promising results, with psychedelics decreasing alcohol drinking and promoting abstinence in individuals with alcohol use disorder. In the last two decades, ayahuasca has emerged as another psychedelic with therapeutic potential for alcohol use disorder. Although its use by indigenous people from South America has been reported for thousands of years, ayahuasca, an Amazonian brewed beverage used in rituals, has gained attention in recent decades due to its reported effects in the central nervous system. Ayahuasca is a hallucinogenic beverage produced from the decoction of Banisteriopsis caapi and Psychotria viridis, plants that contain β-carbolines and N,N-dimethyltryptamine (DMT), respectively. The majority of clinical studies investigating ayahuasca for the treatment of alcohol use disorder are retrospective, and all show a significant decrease in alcohol use among ayahuasca users. Corroborating the clinical evidence, pre-clinical studies also have demonstrated that ayahuasca can block several of the abuse-related effects of alcohol. This chapter reviews the accumulating evidence from clinical and pre-clinical studies suggesting that ayahuasca may be a promising new pharmacotherapy for the treatment of alcohol use disorders, and discusses the potential mechanisms involved in these and other effects of ayahuasca.

The mechanistic divide in psychedelic neuroscience: An unbridgeable gap?

In recent years, psychedelics have generated considerable excitement and interest as potential novel therapeutics for an array of conditions, with the most advanced evidence base in the treatment of certain severe and/or treatment-resistant psychiatric disorders. An array of clinical and pre-clinical evidence has informed our current understanding of how psychedelics produce profound alterations in consciousness. Mechanisms of psychedelic action include receptor binding and downstream cellular and transcriptional pathways, with long-term impacts on brain structure and function-from the level of single neurons to large-scale circuits. In this perspective, we first briefly review and synthesize separate lines of research on potential mechanistic processes underlying the acute and long-term effects of psychedelic compounds, with a particular emphasis on highlighting current theoretical models of psychedelic drug action and their relationships to therapeutic benefits for psychiatric and brain-based disorders. We then highlight an existing area of ongoing controversy we argue is directly informed by theoretical models originating from disparate levels of inquiry, and we ultimately converge on the notion that bridging the current chasm in explanatory models of psychedelic drug action across levels of inquiry (molecular, cellular, circuit, and psychological/behavioral) through innovative methods and collaborative efforts will ultimately yield the comprehensive understanding needed to fully capitalize on the potential therapeutic properties of these compounds.

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.

The Bright Side of Psychedelics: Latest Advances and Challenges in Neuropharmacology

The need to identify effective therapies for the treatment of psychiatric disorders is a particularly important issue in modern societies. In addition, difficulties in finding new drugs have led pharmacologists to review and re-evaluate some past molecules, including psychedelics. For several years there has been growing interest among psychotherapists in psilocybin or lysergic acid diethylamide for the treatment of obsessive-compulsive disorder, of depression, or of post-traumatic stress disorder, although results are not always clear and definitive. In fact, the mechanisms of action of psychedelics are not yet fully understood and some molecular aspects have yet to be well defined. Thus, this review aims to summarize the ethnobotanical uses of the best-known psychedelic plants and the pharmacological mechanisms of the main active ingredients they contain. Furthermore, an up-to-date overview of structural and computational studies performed to evaluate the affinity and binding modes to biologically relevant receptors of ibogaine, mescaline, N,N-dimethyltryptamine, psilocin, and lysergic acid diethylamide is presented. Finally, the most recent clinical studies evaluating the efficacy of psychedelic molecules in some psychiatric disorders are discussed and compared with drugs already used in therapy.

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.

Arketamine, a new rapid-acting antidepressant: A historical review and future directions

The N-methyl-d-aspartate receptor (NMDAR) antagonist (R,S)-ketamine causes rapid onset and sustained antidepressant actions in treatment-resistant patients with major depressive disorder (MDD) and other psychiatric disorders, such as bipolar disorder and post-traumatic stress disorder. (R,S)-ketamine is a racemic mixture consisting of (R)-ketamine (or arketamine) and (S)-ketamine (or esketamine), with (S)-enantiomer having greater affinity for the NMDAR. In 2019, an esketamine nasal spray by Johnson & Johnson was approved in the USA and Europe for treatment-resistant depression. In contrast, an increasing number of preclinical studies show that arketamine has greater potency and longer-lasting antidepressant-like effects than esketamine in rodents, despite the lower binding affinity of arketamine for the NMDAR. Importantly, the side effects, i.e., psychotomimetic and dissociative effects and abuse liability, of arketamine are less than those of (R,S)-ketamine and esketamine in animals and humans. An open-label study demonstrated the rapid and sustained antidepressant effects of arketamine in treatment-resistant patients with MDD. A phase 2 clinical trial of arketamine in treatment-resistant patients with MDD is underway. This study was designed to review the brief history of the novel antidepressant arketamine, the molecular mechanisms underlying its antidepressant actions, and future directions.

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.