Mechanisms Supporting Psilocybin-assisted Psychotherapy for Alcohol Use Disorder: A Randomized, Controlled Clinical Trial

The aim of this study is to determine if a single dose of psilocybin administered with motivational enhancement therapy (MET) can reduce heavy drinking in patients with an alcohol use disorder (AUD). The primary objective of this study is to determine if psilocybin administered with a standardized psychotherapeutic intervention, motivational enhancement therapy (MET), can reduce heavy drinking in a patient population with an alcohol use disorder (AUD). Patients with an AUD will be randomly allocated to either a high dose (25mg; active treatment) or a low dose (1mg; active control) psilocybin arm. All participants will receive 5 sessions of MET, starting at 24hrs post-dosing. Heavy drinking will be assessed as percent heavy drinking days using the Time Line Follow Back (TLFB) at baseline and 1-, 4-, and 12-weeks post-dosing. A total of 128 male and female patients between the ages of 22-65 with a moderate to severe AUD diagnosis will be recruited from the community. Participants will undergo a thorough screening procedure and eligible participants will be randomly allocated to the high (N=64) or low (N=64) psilocybin doses. All participants will complete a baseline session consisting of clinical, behavioral, and neuroimaging measures. Following the single dosing session, participants will complete 5 weekly MET sessions. Neuroimaging measures will be assessed again at 1-week post-doing. Clinical and behavioral outcomes will be measured at 1-, 4-, and 12-weeks post-dosing