Study of Psilocybin vs Niacin for Smoking Cessation in Adults with Tobacco Use Disorder

What this Trial Is About

Researchers are evaluating the use of psilocybin, a 5-HT2A receptor agonist, for helping adults with tobacco use disorder quit smoking. This phase 2, multi-site, double-blind, randomized clinical trial involves 66 participants across four experienced research sites. The study aims to compare psilocybin with niacin, an active placebo, both combined with cognitive behavior therapy CBT, to assess smoking cessation effectiveness and related cognitive changes over 12 months. Participants will be randomly assigned to receive either oral psilocybin or oral niacin in two sessions spaced one week apart. Psilocybin doses are 30 mg in the first session and either 30 mg or 40 mg in the second, depending on responses to a mystical experience questionnaire. Niacin doses are 150 mg in the first session and either 150 mg or 200 mg in the second, following the same dosing schedule. Both groups receive CBT alongside the medication sessions to support quitting smoking. During the study, participants will undergo assessments including cognitive control tasks and questionnaires about smoking urges at screening and shortly after a target quit date. Smoking abstinence will be biochemically confirmed and measured for up to 12 months. Safety and health status will be monitored through interviews, physical exams, ECGs, and lab tests. The trial also investigates psychological factors that may influence quitting success, with overall participation lasting about one year.

5-HT2A Agonist Psilocybin in the Treatment of Tobacco Use Disorder