Physical Exercise in OCD: Treatment Efficacy, Additive Benefits to CBT, and Cognitive Correlates of Change

12 weeks of structured aerobic exercise, 3 times a week, following a two-stage graduated regimen: 1) Initial stage (weeks 1-4): 40-60% intensity, 15-30 min duration (+ 5 min warm-up/cool-down), and 2) Improvement stage (weeks 5-12): 60-80% intensity, 30-45 min duration. Adherence measures include self-reported exercise session logs and weekly phone checks by research assistants.

CBT will be delivered in group format, 2 hours per week, for 12 consecutive weeks with 8-10 participants per group and will be conducted according to a session-by-session treatment manual that incorporates Exposure and Response Prevention (ERP) in the early phases of treatment and then increases emphasis on cognitive approaches for obsessions and compulsions outlined in step-by-step strategies.