The Montreal model of ketamine-therapy for alcohol use disorder and comorbid treatment-resistant depression: protocol for a feasibility trial.

Alcohol use disorder and treatment-resistant depression (TRD) often co-occur, presenting a major clinical challenge with limited effective treatments. However, ketamine produces rapid antidepressant effects and has shown promise in reducing alcohol use, and acceptance and commitment therapy (ACT) can be effective for both substance use and mood disorders. This study explores the feasibility and acceptability of combining ACT with ketamine within the framework of the Montreal Model-a structured, integrative psychedelic ketamine therapy developed for severe TRD. This study is a single-group, open-label feasibility trial at the Centre hospitalier de l'Universit de Montr al (CHUM) Neuromodulation Ketamine Clinic in Montreal, Canada. 30 participants diagnosed with both alcohol use disorder and treatment-resistant depression will receive eight weekly in-person or virtual ACT sessions in addition to six intravenous ketamine infusions. The primary outcome is feasibility, assessed through study completion and protocol adherence. Secondary outcomes include recruitment rate, tolerability, safety, data completeness and healthcare resource use. Exploratory measures will examine changes in depressive symptoms, alcohol use and quality of life using validated tools. A subset of participants will participate in semistructured qualitative interviews to explore their experiences. This study was approved by the ethics committee of the CHUM on 14 May 2025. The results of the trial, including primary and secondary outcomes, will be published in peer-reviewed scientific journals. NCT06620276.