This Phase II, randomised, double-blind trial (n=30) will evaluate the feasibility and preliminary efficacy of psilocybin-assisted psychotherapy for individuals diagnosed with gambling disorder. Participants will be assigned to receive either high-dose psilocybin (25 mg or 40 mg, depending on response) or low-dose psilocybin (1 mg) in conjunction with psychotherapy. The primary outcome will be the protocol completion rate over a 33-month period. The study aims to assess the retention of participants throughout the trial and gather initial data on the therapeutic effects of psilocybin, as well as identify clinical factors influencing the intensity of the psychedelic experience. Participants must be aged 18 or older, have a confirmed diagnosis of gambling disorder, and meet various inclusion criteria, including the ability to complete self-assessment questionnaires and willingness to undergo medical tests. The trial is set to commence in April 2026 and is sponsored by Nantes University Hospital.
The PASSENGER project aims to conduct a pilot feasibility study of the implementation of a randomized clinical trial on psilocybin-assisted psychotherapy for the treatment of gambling disorder. Feasibility will be assessed by estimating the ability to retain participants until the end of the protocol. Other objectives of the study will be to generate preliminary efficacy data, identify clinical factors potentially associated with the intensity of the psychedelic experience (which determines the expected therapeutic effect), and conduct a preliminary assessment of the safety of the treatment under study.