A pilot randomized controlled trial of aerobic exercise as an adjunct to OCD treatment

Objective: The purpose of the current study was to conduct a randomized controlled trial testing the efficacy of aerobic exercise for decreasing OCD symptom severity, other mental health outcomes, and increasing exercise behaviors and cardiorespiratory fitness among individuals with OCD. Method: Fifty-six patients (64% female; mean age = 38.8 years) with OCD and a Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score of 16 or greater despite engaging in OCD treatment were randomized to 12-weeks of supervised plus home-based moderate-intensity aerobic exercise (AE; n = 28) or to 12-weeks of health education sessions (HE; n = 28). Results: Random intercepts mixed models examined differences between conditions at post-treatment. Though no difference between conditions on outcomes was observed, both AE and HE showed significant reduction in OCD symptom severity, depression and anxiety at post-treatment. Relative to HE, significant increases were noted in amount of exercise and cardiorespiratory fitness for those in the AE condition. At post-treatment, 30.4% of the AE condition (7 of 23) were treatment-responders (using the commonly accepted measure of 35% symptom reduction from baseline). In the HE condition, 7.7% of the sample (2 of 26) met this criterion at post-treatment. Conclusion: The results of this preliminary study suggest that exercise and health-focused interventions may be beneficial adjuncts to existing OCD treatment. Future studies with larger samples are needed to more definitively answer questions the efficacy of AE for reducing OCD symptoms and improving related clinical outcomes.