Effects of Ayahuasca on Personality: Results of Two Randomized, Placebo-Controlled Trials in Healthy Volunteers
Frontiers in Psychiatry – August 06, 2021
Source: OpenAlex
Summary
A compelling psychology finding: the hallucinogen Ayahuasca, a complex plant alkaloid, may influence personality. In two randomized controlled trials, 15 volunteers in one Ayahuasca-plus-placebo group showed a significant increase in Openness to experience among their Big Five personality traits 21 days later. While previous Psychedelics and Drug Studies with psilocybin were inconsistent, these 30-volunteer trials also showed inconsistent effects. Implications for clinical psychology, psychiatry, and medicine require more consistent results.
Abstract
Rationale: Previous studies with the serotonergic hallucinogens LSD and psilocybin showed that these drugs induced changes in personality traits, such as increases in Openness. However, results are inconsistent, and the effects of ayahuasca on personality were never investigated in a controlled trial. Objectives: To assess the effects of ayahuasca on personality in two randomized, placebo-controlled trials in healthy volunteers. Methods: Data from two parallel-group, randomized, placebo-controlled trials in healthy volunteers were included. In the first trial, 15 volunteers ingested ayahuasca or placebo, while in the second trial 15 volunteers received placebo+ayahuasca or cannabidiol (CBD)+ayahuasca. Personality was assessed with the NEO-Five Factor Inventory (NEO-FFI) at baseline and 21 days post-treatment. Results: There were significant differences between groups in baseline Openness scores, but not on day 21. A significant increase in Openness scores was observed in the placebo + ayahuasca group in study 2. No other within-group differences were observed for any other domain. Conclusions: Ayahuasca produced inconsistent effects on personality since it induced significant increase in Openness 21 days post-drug intake only in one of the trials. The absence of significant differences in the other ayahuasca groups could be due to small sample sizes and baseline differences among groups. The effects of ayahuasca and other serotonergic hallucinogens on personality should be further investigated in clinical samples.