A placebo-controlled study of the effects of ayahuasca, set and setting on mental health of participants in ayahuasca group retreats.

Ayahuasca is a plant concoction containing N,N-dimethyltryptamine (DMT) and certain ß-carboline alkaloids from South America. Previous research in naturalistic settings has suggested that ingestion of ayahuasca can improve mental health and well-being; however, these studies were not placebo controlled and did not control for the possibility of expectation bias. This naturalistic observational study was designed to assess whether mental health changes were produced by ayahuasca or by set and setting. Assessments were made pre- and post-ayahuasca sessions in 30 experienced participants of ayahuasca retreats hosted in the Netherlands, Spain, and Germany. Participants consumed ayahuasca (N = 14) or placebo (N = 16). Analysis revealed a main effect of time on symptoms of depression, anxiety, and stress. Compared to baseline, symptoms reduced in both groups after the ceremony, independent of treatment. There was a main treatment × time interaction on implicit emotional empathy, indicating that ayahuasca increased emotional empathy to negative stimuli. The current findings suggest that improvements in mental health of participants of ayahuasca ceremonies can be driven by non-pharmacological factors that constitute a placebo response but also by pharmacological factors that are related to the use of ayahuasca. These findings stress the importance of placebo-controlled designs in psychedelic research and the need to further explore the contribution of non-pharmacological factors to the psychedelic experience.

Do reminders of the crime reverse the memory-undermining effect of simulating amnesia?

Research shows that simulating amnesia impairs actual memory for a mock crime. Lack of rehearsal has been suggested as the most likely explanation for this finding because feigning amnesia is linked to reduced thinking about the offence. We investigated whether reminders about the crime could reverse the memory-undermining effect of simulation. In two studies, participants watched a video of a violent crime. After, they were asked to either simulate amnesia or confess the crime. During the week between the first and second memory test phase, participants were provided with reminders of the crime in two different modalities. In Study 1 (pilot), participants received frames of the mock crime video via WhatsApp. Findings showed that such reminders did not enhance ex-simulators' memory. In Study 2, participants were asked to put sequences of the mock crime in the right order. This latter modality led to enhanced memory for the offence in simulating participants. Theoretical and practical implications of our findings for the legal field are discussed.

A single inhalation of vapor from dried toad secretion containing 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) in a naturalistic setting is related to sustained enhancement of satisfaction with life, mindfulness-related capacities, and a decrement of psychopathological symptoms.

BACKGROUND: 5-methoxy-N,N-dimethyltryptamine (hereinafter referred to as 5-MeO-DMT) is a psychedelic substance found in the secretion from the parotoid glands of the Bufo alvarius toad. Inhalation of vapor from toad secretion containing 5-MeO-DMT has become popular in naturalistic settings as a treatment of mental health problems or as a means for spiritual exploration. However, knowledge of the effects of 5-MeO-DMT in humans is limited. AIMS: The first objective of this study was to assess sub-acute and long-term effects of inhaling vapor from dried toad secretion containing 5-MeO-DMT on affect and cognition. The second objective was to assess whether any changes were associated with the psychedelic experience. METHODS: Assessments at baseline, within 24 h and 4 weeks following intake, were made in 42 individuals who inhaled vapor from dried toad secretion at several European locations. RESULTS: Relative to baseline, ratings of satisfaction with life and convergent thinking significantly increased right after intake and were maintained at follow-up 4 weeks later. Ratings of mindfulness also increased over time and reached statistical significance at 4 weeks. Ratings of depression, anxiety, and stress decreased after the session, and reached significance at 4 weeks. Participants that experienced high levels of ego dissolution or oceanic boundlessness during the session displayed higher ratings of satisfaction with life and lower ratings of depression and stress. CONCLUSION: A single inhalation of vapor from dried toad secretion containing 5-MeO-DMT produces sub-acute and long-term changes in affect and cognition in volunteers. These results warrant exploratory research into therapeutic applications of 5-MeO-DMT.

Sub-acute and long-term effects of ayahuasca on affect and cognitive thinking style and their association with ego dissolution.

RATIONALE: Ayahuasca is a psychotropic plant tea from South America used for religious purposes by indigenous people of the Amazon. Increasing evidence indicates that ayahuasca may have therapeutic potential in the treatment of mental health disorders and can enhance mindfulness-related capacities. Most research so far has focused on acute and sub-acute effects of ayahuasca on mental health-related parameters and less on long-term effects. OBJECTIVES: The present study aimed to assess sub-acute and long-term effects of ayahuasca on well-being and cognitive thinking style. The second objective was to assess whether sub-acute and long-term effects of ayahuasca depend on the degree of ego dissolution that was experienced after consumption of ayahuasca. RESULTS: Ayahuasca ceremony attendants (N = 57) in the Netherlands and Colombia were assessed before, the day after, and 4 weeks following the ritual. Relative to baseline, ratings of depression and stress significantly decreased after the ayahuasca ceremony and these changes persisted for 4 weeks. Likewise, convergent thinking improved post-ayahuasca ceremony up until the 4 weeks follow-up. Satisfaction with life and several aspects of mindfulness increased the day after the ceremony, but these changes failed to reach significance 4 weeks after. Changes in affect, satisfaction with life, and mindfulness were significantly correlated to the level of ego dissolution experienced during the ayahuasca ceremony and were unrelated to previous experience with ayahuasca. CONCLUSION: It is concluded that ayahuasca produces sub-acute and long-term improvements in affect and cognitive thinking style in non-pathological users. These data highlight the therapeutic potential of ayahuasca in the treatment of mental health disorders, such as depression.

The relationship between psychopathy and crime-related amnesia.

The objective of this study was to investigate whether levels of psychopathy predicted claims of crime-related amnesia. Different characteristics of psychopathy were based on the factor structure of the self-report questionnaire Psychopathic Personality Inventory (PPI). Crime-related amnesia claims were scored from inmates (N=31) criminal file records. Results demonstrated that claims of crime-related amnesia were more frequently reported by individuals scoring high on impulsive antisocial psychopathy traits. Furthermore, offenders who claimed crime-related amnesia reported lower levels of instrumental/proactive aggression. There was no relationship between fearless-callous psychopathy traits or the use of reactive violence, and claims of crime-related amnesia. Within offenders who claimed amnesia for their crime, the majority demonstrated elevated levels of deception, suggesting that claims of amnesia might serve a strategic purpose. In addition, they more often reported having had a previous experience with memory loss, which may have formed the basis of simulation.