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Psilocybin for alcohol use disorder: Rationale and design considerations for a randomized controlled trial.

Kelley C O'Donnell, Sarah E. Mennenga, Lindsey T. Owens, Samantha K. Podrebarac, Tara Baron, John Rotrosen, Stephen Ross, Alyssa A. Forcehimes, Michael P. Bogenschutz

Contemporary Clinical Trials December 1, 2022 DOI: 10.1016/j.cct.2022.106976 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Randomized controlled trial Double-blind Open-label Peer reviewed
Sample size 96
Population Alcohol-dependent volunteers
Interventions Psilocybin Diphenhydramine
Dose 25 mg/70 kg psilocybin or 50 mg diphenhydramine
Duration 12-week psychotherapy platform, two dosing sessions at weeks 4 and 8, follow-up through week 36
Topics Addiction Psilocybin Psychedelic-assisted therapy
Keywords Alcohol Clinical trial design Addiction treatment Clinical research Substance abuse Psilocybin studies
Citations 24
Key findings The paper describes the protocol and rationale for a randomized trial testing psilocybin-assisted psychotherapy for alcohol dependence, with primary outcomes to be reported elsewhere.

Abstract

Several lines of evidence suggest that classic psychedelics (5-HT2A receptor agonists or partial agonists) such as psilocybin might facilitate behavior change in individuals with substance use disorders. We conducted a multi-site, double-blind, randomized controlled trial (RCT) to assess the effects of psilocybin-assisted psychotherapy in alcohol-dependent volunteers. In addition to a structured 12-week psychotherapy platform, participants (n = 96) were randomly assigned (1:1) to receive either oral psilocybin or an active placebo (oral diphenhydramine) in each of two dosing sessions (at weeks 4 and 8). Initial doses were 25 mg/70 kg psilocybin or 50 mg diphenhydramine, which could be increased in the second session depending on initial response. The psychotherapy platform combined evidence-based, manualized therapy for alcohol dependence with a supportive context for the dosing sessions. All participants were followed in the RCT through week 36. At the end of the RCT, participants who still met safety criteria were offered an open-label psilocybin session. Data collected at screening, baseline and throughout the study included: demographics, measures of alcohol use, subjective response to psilocybin and diphenhydramine, and safety measures. The primary outcome was the proportion of heavy drinking days during the 32 weeks after the first dosing session (i.e., between week 4 and week 36). Secondary outcomes included safety, additional measures of drinking (e.g., abstinence, drinking days, etc.), craving, self-efficacy, and acute effects. We will also explore moderators and mediators of the primary outcome. The primary outcomes will be published elsewhere. In this paper, we describe the protocol and rationale for our design decisions.

Comparable studies

Other randomized controlled trials on psilocybin for addiction, most cited first.

Study Year Design Participants
Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder Adults aged 25–65 with DSM-IV alcohol dependence and at least 4 heavy drinking days in... 2022 Randomized controlled trial n = 95
Clinical Interpretations of Patient Experience in a Trial of Psilocybin-Assisted Psychotherapy for Alcohol Use Disorder Participants in an ongoing trial of psilocybin-assisted treatment for alcohol use disorder 2018 Double-blind placebo-controlled clinical trial n = 3
Psilocybin-assisted therapy for relapse prevention in alcohol use disorder: a phase 2 randomized clinical trial Patients with alcohol use disorder 2025 Randomized controlled trial
Psilocybin-induced changes in neural reactivity to alcohol and emotional cues in patients with alcohol use disorder: an fMRI pilot study Adult patients with alcohol use disorder 2024 Pilot study; randomized, double-blind, placebo-controlled clinical trial n = 11
Multidimensional Personality Changes Following Psilocybin-Assisted Therapy in Patients With Alcohol Use Disorder: Results From a Double-Blind, Placebo-Controlled Clinical Trial People with alcohol use disorder 2025 Randomized controlled trial

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