Efficacy of exposure and response prevention therapy in mixed reality for patients with obsessive-compulsive disorder: study protocol for a randomized controlled trial.

Many patients with obsessive-compulsive disorder (OCD) do not receive cognitive behavioral therapy with exposure and response prevention (first line treatment for OCD), for example, due to patients' fear of the exposure and reservations of the therapists. Technology-supported exposure (e.g., exposure therapy with response prevention in mixed reality [MERP]) for patients with OCD may help to overcome this obstacle. Building upon findings of our pilot study objectives of this study are to evaluate the efficacy, expectations of treatment success, feasibility, and acceptance of MERP as well as to identify possible limitations. In total, 64 outpatients with contamination-related OCD will be recruited and randomized to one of two conditions: MERP (six sessions in six weeks) and self-guided exposure therapy (six exercises in six weeks). Participants will be assessed before (baseline), after the six-week intervention period (post), as well as three months after post assessment (follow-up) regarding symptomatology (Yale-Brown Obsessive Compulsive Scale; Y-BOCS), their subjective evaluation of MERP (acceptance) and sense of presence. The planned study is the first to investigate MERP in patients with OCD.