Effects of Ayahuasca on Personality: Results of Two Randomized, Placebo-Controlled Trials in Healthy Volunteers
Juliana Mendes Rocha, Giordano Novak Rossi, Flávia de Lima Osório, José Carlos Bouso, Gabriela de Oliveira Silveira, Maurı́cio Yonamine, Eduardo José Crevelin, Maria Eugênia Costa Queiroz, Jaime E. C. Hallak, Rafael G. Dos Santos
Frontiers in Psychiatry August 6, 2021 DOI: 10.3389/fpsyt.2021.688439 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Placebo-controlled Peer reviewed |
|---|---|
| Sample size | 30 |
| Population | Healthy volunteers |
| Interventions | Ayahuasca Placebo Cannabidiol |
| Duration | 21-day follow-up |
| Topics | Ayahuasca Psilocybin |
| Keywords | Placebo Hallucinogen Personality Randomized controlled trial Openness to experience Clinical psychology |
| Citations | 37 |
| Key findings | Ayahuasca produced a significant increase in Openness scores 21 days post-drug intake in only one of two trials, indicating inconsistent effects on personality. |
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.