Psilocybin, a psychodelic derived from fungi, has been shown to significantly reduce alcohol consumption in patients with alcohol dependence, although the mechanism of action has not been established.
This was a double-blind, randomized trial. The patients were 25-65 years of age who were diagnosed with alcohol dependence and had 4 days of heavy alcohol consumption during the previous 30-day period.
All patients received weekly psychotherapy for 12 weeks that consisted of motivational enhancement therapy and cognitive behavioral therapy. In addition, the patients received 2-day medical treatment sessions in weeks 4 and 8 with psilocybin (25 mg/70 kg [session 1] and 25-40 mg/70 kg [session 2]) or diphenhydramine (50 mg [session 1] and 50-100 mg [session 2]). The primary outcome was the percentage of heavy drinking days over a 32-week period.
Ninety-five patients were enrolled in the study (mean age = 46 y; females = 44.2%; ethnicities = American Indian/Alaska Native, Black, Hispanic, and non-Hispanic White).
Patients who were treated with psilocybin + psychotherapy had fewer heavy alcohol consumption days than patients who were treated with diphenhydramine + psychotherapy (9.7% vs. 23.6%). The mean daily alcohol consumption was also lower in the psilocybin + psychotherapy group.