A Double-Blind Trial of Psilocybin-Assisted Treatment of Alcohol Dependence
Several lines of evidence suggest that classic hallucinogens such as psilocybin can facilitate behaviour change in addictions such as alcohol dependence. The investigation is a multi-site, double-blind, active-controlled trial (n=95, 47 per group) contrasting the acute and persisting effects of psilocybin to those of diphenhydramine (placebo) in the context of outpatient alcoholism treatment.
Details
Randomized, quadruple-blind, parallel-group Phase II trial comparing psilocybin-assisted therapy to diphenhydramine control in participants with alcohol dependence; manualized Motivational Enhancement and Taking Action (META) therapy provided across the double-blind period.
Psilocybin is given in two 8-hour outpatient dosing sessions at weeks 4 and 8 (initial dose 25 mg/70 kg; second session may be 25, 30, or 40 mg/70 kg). Diphenhydramine comparator given 50 mg (may increase to 100 mg) on the same schedule. Outcomes include drinking behavior up to 50 weeks after first administration (total follow-up ~54 weeks), craving, self-efficacy, motivation, mood, and spiritual measures.
Extensive screening, medical safety monitoring, and post-session debriefing/integration are included; participants meeting interim safety criteria may be offered an additional open-label psilocybin session after the double-blind period.