Psilocybin's controlled evidence for alcohol use disorder ends at week 36, while an uncontrolled repeat-dose follow-up found only brief reductions

The strongest controlled evidence for psilocybin in alcohol use disorder comes from a 2022 NYU trial of 93 dosed patients, which found fewer heavy drinking days with psilocybin than with diphenhydramine through week 36. Its planned endpoint leaves durability beyond roughly eight months unanswered. A new four-month open-label extension gave 59 former participants one additional dose without blinding or a control group. Among those still drinking heavily, heavy drinking days, drinks per day and drinking days declined at month one, then returned to entry levels. The study cannot distinguish a short drug effect from expectancy, regression to the mean or treatment differences, while remission among initially abstinent participants is difficult to interpret without a comparator. Other small controlled trials disagree, and the two largest ongoing trials end randomized comparisons at weeks 24 and roughly 26. Longer-term controlled evidence therefore remains unavailable.