ABSTRACT
BACKGROUND: Ayahuasca is a South American plant hallucinogen rich in the psychedelic N,N-dimethyltryptamine and ß-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. METHODS: 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. FINDINGS: 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. CONCLUSIONS: 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.
ABSTRACT
The recognition of emotions in facial expressions (REFE) is a core construct of social cognition. In the last decades, studies have showed that REFE is altered in major depressive disorder (MDD), but the evidence is conflicting. Thus, we conducted a systematic review of clinical trials involving therapeutic interventions in MDD and any evaluation of REFE to update (2018-2023) and systematically evaluate the evidence derived from controlled clinical trials on the effects of therapeutic strategies to MDD on the REFE. Eleven studies were included in the final review. Some interventions, including drugs (ketamine, bupropion, psylocibin) and non-pharmacological strategies (psychotherapy) seem to be able to reduce pre-existing REFE biases in MDD patients. However, there was a high heterogeneity in the evaluated studies, in terms of sample, interventions, tasks and results. Further studies and more consistent evaluation tools are highly needed to better understand nuanced deficits and specific actions of different treatment options.
