Abstract
Introduction: Physical exercise administered before or after exposure has been shown to have beneficial effects on treatment outcomes in anxiety- and trauma-related disor-ders. However, this approach has not yet been examined for obsessive–compulsive dis-order (OCD). This randomized controlled trial investigated whether high-intensity exer-cise administered immediately after exposure therapy improves treatment outcomes in patients with obsessive-compulsive disorder (OCD). Methods: Ninety-seven inpatients with OCD participated in an eight-week exposure-based treatment phase during inpa-tient care, comprising two sessions per week, and were randomly assigned to either high-intensity exercise (ExpoHI) or low-intensity control (ExpoLI) administered immedi-ately after a standardized exposure and response prevention (ERP) session. OCD se-verity was assessed using the Yale–Brown Obsessive Compulsive Scale (Y-BOCS) at admission, discharge, and six-month follow-up. The secondary outcomes included gen-eral psychopathological symptoms. Results: ExpoHI showed significantly greater reduc-tions in Y-BOCS scores at discharge (between-group difference: −3.14 points, p = .009), corresponding to a moderate-to-large between-group effect size (Cohen’s d = 0.76), which was maintained at the six-month follow-up (p = .030; Cohen’s d = 0.68). Re-sponder rates at discharge were significantly higher in the ExpoHI group (85.4%) than in the ExpoLI group (61.2%) (p = .011), whereas remission rates did not differ between groups. ExpoHI also showed greater reductions in depressive symptoms at follow-up. Conclusions: High-intensity exercise immediately following exposure therapy produced greater reductions in obsessive–compulsive symptoms than the active control condition. These findings suggest that exercise may be a feasible adjunct for exposure-based treatment.