Effects of a Single Dose of Ayahuasca in College Students With Harmful Alcohol Use: A Single-blind, Feasibility, Proof-of-Concept Trial.

A single dose of ayahuasca, a plant hallucinogen containing N,N-dimethyltryptamine and harmine, was given with psychological support to 11 college students who drank alcohol harmfully. The treatment was well tolerated and produced strong psychoactive effects. Days of alcohol consumption per week dropped from about 2.9 to 2.1 between weeks 2 and 3, but this reduction was not statistically significant after correcting for multiple comparisons. No other measures—craving, anxiety, impulsivity, self-esteem, or social cognition—showed significant changes, except faster reaction time on an empathy task. The small sample and mild baseline drinking likely limited the findings. The study demonstrates the protocol is feasible for future larger trials.

Study at a glance

Abstract

Ayahuasca is a South American plant hallucinogen rich in the psychedelic N,N-dimethyltryptamine and β-carbolines (mainly harmine). Preclinical and observational studies suggest that ayahuasca exerts beneficial effects in substance use disorders, but these potentials were never assessed in a clinical trial. Single-center, single-blind, feasibility, proof-of-concept study, assessing the effects of one dose of ayahuasca accompanied by psychological support (without psychotherapy) on the drinking patterns (primary variable) of 11 college students with harmful alcohol consumption. Secondary variables included safety and tolerability, craving, personality, anxiety, impulsivity, self-esteem, and social cognition. Ayahuasca was well tolerated (no serious adverse reactions were observed), while producing significant psychoactive effects. Significant reductions in days per week of alcohol consumption were found between weeks 2 and 3 (2.90 ± 0.28 vs 2.09 ± 0.41; P < 0.05, uncorrected), which were not statistically significant after Bonferroni correction. There were no statistically significant effects for other variables, except for a significant reduction in reaction time in an empathy task. A significant reduction in days of alcohol consumption was observed 2-3 weeks after ayahuasca intake, but this effect did not survive after Bonferroni correction. The lack of significant effects in alcohol use and other variables may be related to the small sample size and mild/moderate alcohol use at baseline. The present study shows the feasibility of our protocol, paving the way for future larger, controlled studies.