Johns Hopkins Psilocybin Trial Helps Smokers Stub Out Habit

Johns Hopkins researchers say a single high dose of psilocybin, delivered in a tightly supervised clinical setting alongside structured therapy, sharply boosted six-month quit rates in a small randomized trial of smokers. Roughly 40% of people who got psilocybin were biochemically verified as having prolonged abstinence at six months, compared with about 10% of those assigned to a nicotine patch.

The pilot study enrolled 82 adult smokers and randomly assigned them to either psilocybin plus therapy or a standard nicotine-patch regimen, according to JAMA Network Open. At the six-month primary endpoint, 17 participants in the psilocybin arm (40.5%) met biochemically verified prolonged abstinence versus 4 participants in the patch arm (10.0%), an odds ratio of 6.12 (95% CI, 1.99–23.26; P = .003). In a field where single-digit improvements usually count as progress, that gap stands out.

How the trial worked

The trial, run at Johns Hopkins Bayview Medical Center, enrolled psychiatrically healthy adults who smoked a mean of about 16 cigarettes per day. Participants randomized to psilocybin received a single high dose (30 mg/70 kg) scheduled for the study’s target quit date, while control participants began an 8 to 10-week nicotine-patch course. Both groups completed a 13-week manualized cognitive behavioral therapy program, according to the study dataset on Mendeley Data.

What researchers and experts said

“I was surprised by the sheer magnitude of the effect,” study author Matthew Johnson said. Outside specialists told reporters the compound likely works by triggering a perspective shift that strengthens the impact of therapy, as reported by WFAE/NPR. Addiction psychiatrist Brian Barnett described psilocybin as “a very different treatment approach” from nicotine replacement, while Megan Piper called the findings an “exciting” proof-of-concept for a novel strategy.

Limits and safety signals

The authors stress that the findings are preliminary. The sample was small, about 89% of participants were White, and both participants and investigators knew which treatment was given, a setup that can inflate effect sizes. Safety events were mostly short-lived but still notable, with headaches and brief blood-pressure elevations more common in the psilocybin arm, as the authors report in JAMA Network Open.

What’s next

Investigators say the results need to be replicated and better understood. A larger, multisite trial funded by the National Institute on Drug Abuse is already underway and is registered as NCT05452772 on ClinicalTrials.gov. The current paper notes that longer-term follow-ups, crossover findings, and brain-imaging analyses are planned for separate publications.

Even if bigger trials confirm a benefit, psilocybin-assisted cessation is unlikely to become an off-the-shelf solution. The approach depends on carefully controlled dosing, trained facilitators, and structured therapy. That level of support is no small detail when cigarette smoking remains the leading preventable cause of death in the United States, accounting for roughly 480,000 deaths a year, according to the CDC.