Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction

In an open-label pilot study, 15 nicotine-dependent smokers received moderate (20 mg/70 kg) and high (30 mg/70 kg) doses of psilocybin as part of a structured 15-week smoking cessation program. At 6-month follow-up, 12 of 15 participants (80%) showed seven-day point prevalence abstinence, a rate substantially exceeding the typical 35% or less reported for other behavioral or pharmacological therapies. The authors note the open-label design prevents definitive conclusions about efficacy, but the findings suggest psilocybin may be a potentially useful adjunct to smoking cessation treatment.

Study at a glance

Abstract

Despite suggestive early findings on the therapeutic use of hallucinogens in the treatment of substance use disorders, rigorous follow-up has not been conducted. To determine the safety and feasibility of psilocybin as an adjunct to tobacco smoking cessation treatment we conducted an open-label pilot study administering moderate (20 mg/70 kg) and high (30 mg/70 kg) doses of psilocybin within a structured 15-week smoking cessation treatment protocol. Participants were 15 psychiatrically healthy nicotine-dependent smokers (10 males; mean age of 51 years), with a mean of six previous lifetime quit attempts, and smoking a mean of 19 cigarettes per day for a mean of 31 years at intake. Biomarkers assessing smoking status, and self-report measures of smoking behavior demonstrated that 12 of 15 participants (80%) showed seven-day point prevalence abstinence at 6-month follow-up. The observed smoking cessation rate substantially exceeds rates commonly reported for other behavioral and/or pharmacological therapies (typically <35%). Although the open-label design does not allow for definitive conclusions regarding the efficacy of psilocybin, these findings suggest psilocybin may be a potentially efficacious adjunct to current smoking cessation treatment models. The present study illustrates a framework for future research on the efficacy and mechanisms of hallucinogen-facilitated treatment of addiction.