Substance Use Disorders: psilocybin research evidence

Evidence by substance

Alcohol use disorder

A randomised trial found that psilocybin-assisted psychotherapy reduced heavy drinking days compared with active placebo plus psychotherapy — one of the stronger modern addiction signals. An earlier open-label proof-of-concept study similarly linked supervised psilocybin plus motivational enhancement to increased abstinence through 36 weeks.

Tobacco / nicotine

An open-label pilot reported unusually high abstinence rates when psilocybin was paired with structured behavioural support. Long-term follow-up found biologically verified abstinence of about two-thirds at 12 months and roughly 60% at multi-year follow-up. Controlled replication remains important before broad clinical claims.

Cocaine

A 2026 randomised, quadruple-blind trial reported higher cocaine-abstinent days, greater odds of complete abstinence, and lower lapse hazard after psilocybin versus active placebo through 180 days, with no serious adverse events in the reported cohort.

Other substances

Opioid, stimulant (beyond cocaine), and behavioural addiction data remain thinner. Mechanistic optimism should not outrun the evidence.

Interpretation standard

PSILORIS marks substance use disorders promising because multiple major indications now have controlled or strong pilot evidence. That does not mean psilocybin is a stand-alone addiction cure or appropriate outside integrated psychosocial care.