Two doses of psilocybin, a compound found in psychedelic mushrooms, reduces heavy drinking by 83% on average among heavy drinkers when combined with psychotherapy, a new study shows. Led by researchers at the New York University (NYU) Grossman School of Medicine, the investigation involved 93 men and women with alcohol dependence. They were randomly assigned to receive either two doses of psilocybin or an antihistamine placebo. Neither the researchers nor the study participants knew which medication they received. Within an eight-month period from the start of their treatment, those who were given psilocybin reduced heavy drinking by 83% relative to their drinking before the study began. Meanwhile, those who had received antihistamine reduced their drinking by 51%. Among the other key findings, the study showed that eight months after their first dose, almost half (48%) of those who received psilocybin stopped drinking altogether compared with 24% of the placebo group. “Our findings strongly suggest that psilocybin therapy is a promising means of treating alcohol use disorder, a complex disease that has proven notoriously difficult to manage,” says study senior author and psychiatrist Michael Bogenschutz, MD, Director of the NYU Langone Center for Psychedelic Medicine.