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 wit h and without medication. Eighty-seven OCD patients were divided into nonde pressed 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 wit h 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 attenua ted outcome.