Johnson · The American journal of drug and alcohol abuse 2017 · Open-label single-arm follow-up study · n=15

Long-term follow-up of psilocybin-facilitated smoking cessation.

Cited 709 times in the scientific literature.

Level 4 - case-series / case-control

Open-label, single-arm pilot study follow-up without a control group

PubMed 27441452 · doi:10.3109/00952990.2016.1170135 · record verified 2026-08-30

What was done

This study evaluated long-term outcomes of an open-label pilot trial where 15 participants received 2 to 3 moderate to high doses (20 and 30 mg/70 kg) of psilocybin combined with cognitive behavioral therapy (CBT) for smoking cessation. Biologically verified smoking abstinence and subjective ratings of psilocybin experiences were measured at 12 months and at a long-term follow-up (≥16 months post-target quit date).

What was found

All 15 participants completed the 12-month follow-up, and 12 (80%) completed the long-term follow-up (mean 30 months, range 16–57 months). Biologically confirmed smoking abstinence was 67% (10/15) at 12 months and 60% (9/15) at long-term follow-up. At 12 months, 86.7% of participants (13/15) rated their psilocybin experiences among the five most personally meaningful and spiritually significant experiences of their lives.

Why it matters

This study suggests that psilocybin combined with behavioral therapy can produce sustained smoking abstinence over several years, supporting further investigation in larger controlled trials.

Limits

The study is an open-label, single-arm pilot with a very small sample size (n = 15) and no control group, precluding causal attribution to psilocybin versus CBT or placebo effects. Three participants (20%) were lost to follow-up at the long-term timepoint.

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