Evaluating the Therapeutic Effects of Ayahuasca: A Naturalistic Longitudinal Study on Alcohol Use, Mental Wellbeing, and the Mystical Experience

Abstract

Background: Research into ayahuasca, an Amazonian brewed psychedelic tea, has expanded in recent decades, moving from observational and cross-sectional studies to longitudinal naturalistic studies and clinical trials in recent years. This growing body of evidence suggests that ayahuasca may improve mental wellbeing and reduce substance use. Longitudinal evidence in recreational substance-using populations remains limited, however, and the role of the mystical experience as a potential moderator of therapeutic outcomes is poorly understood.Objective: This study aimed to examine changes in mental wellbeing and alcohol use frequency following participation in a structured ayahuasca retreat in recreational substance users who did not meet criteria for substance use disorder in the past month, and to investigate whether the intensity of participants' mystical experiences moderated these changes. Methods and Analysis: This naturalistic longitudinal study recruited 123 participants attending an ayahuasca retreat. Mental wellbeing was assessed using WEMWBS and alcohol use frequency was measured at baseline and one-month follow-up. Mystical experience was measured post-retreat using the MEQ-30. Mixed effects models were used to examine pre-to-post changes in WEMWBS scores and alcohol use frequency. Gender identity, age, and mental health diagnosis were included as covariates, and MEQ-30 scores and a binary CME classification were examined as moderators. Results: WEMWBS scores improved significantly from baseline to one-month follow-up (β = 8.31, 95% CI [6.18, 10.37]). Alcohol use frequency decreased significantly over the same period (OR = 0.49, 95% CI [0.25, 0.96], p = .036). Presence of a mental health diagnosis was associated with lower overall wellbeing scores, though descriptive data suggested a larger raw score improvement in the diagnosed group. The proportion of participants reporting frequent alcohol use reduced from 10.8% at baseline to 1.4% at follow-up. Neither MEQ-30 total score nor the CME classification significantly moderated either outcome. Discussion: Ayahuasca retreat participation was associated with significant improvements in mental wellbeing and reductions in alcohol use frequency. These findings extend the existing literature to a previously understudied population, demonstrating that the therapeutic benefits of ayahuasca may be applicable to a broader population, and support continued investigation into ayahuasca's therapeutic potential.