MDMA-assisted psychotherapy for AUD: Bayesian analysis of WHO drinking risk level and exploratory analysis of drinking behavior and psychosocial functioning at 3 months follow-up

Aims: Safety and tolerability data from the first open-label feasibility study of 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for alcohol use disorder was recently published. This paper presents a Bayesian analysis of the impact of MDMA-assisted psychotherapy on treatment success, defined as 2-level reduction in the World Health Organization (WHO) drinking risk at the 3 months follow-up. We also examined the impact on drinking behavior and psychosocial measures at 3 months compared to baseline.Methods: Fourteen participants with a diagnosis of alcohol use disorder who had recently undergone detoxification completed an eight-week course of ten psychotherapy sessions, including two sessions with MDMA. Measures assessing drinking behavior, quality of life, sleep, self-compassion, and empathy were collected. Bayesian analysis using flat and skeptical priors was performed to determine treatment success defined as a 2-level reduction in WHO drinking risk.Results: Bayesian analysis suggested that the probability of a 2-level reduction in WHO drinking risk from baseline to 3 months post-treatment is 55%-63%, based upon either a flat or skeptical prior respectively. We present preliminary findings suggesting reductions in alcohol craving (measured by the Penn Alcohol Craving Scale and Obsessive Compulsive Drinking Scale) and improvements in sleep and aspects of psychosocial functioning at 3 months follow-up compared to baseline.Conclusions: The Bayesian analysis provides a useful harm reduction endpoint interpretation of drinking in terms of a 2-level reduction in WHO drinking risk. Further findings provide preliminary insights into the potential impact of MDMA-assisted psychotherapy on quality of life and well-being in addition to reductions in drinking.