Effects of comorbid depression on response to treatment for obsessive-compulsive disorder

We examined the effects of comorbid depression on response to treatment for obsessive-compulsive disorder (OCD) using cognitive-behavioral therapy with and without medication. Eighty-seven OCD patients were divided into nondepressed and mildly, moderately, and severely depressed groups on the basis of their pretreatment Beck Depression Inventory (BDI) scores. Each received an intensive cognitive-behavioral treatment program involving exposure with response prevention (EX/RP); 59 (68%) were also taking medication for OCD. Patients with severe initial depression (BDI greater than or equal to 30) showed significantly less improvement compared to those less depressed or nondepressed; yet, even highly depressed patients showed moderate treatment gains. Failure to habituate to anxiety-evoking stimuli during exposure and a lack of motivation for therapy are considered possible causes of attenuated outcome.