Cognitive-behaviour therapy and medication in the treatment of obsessive-compulsive disorder: a controlled study.

OBJECTIVE To evaluate the effect of combining cognitive-behaviour therapy (CBT) and medication in the treatment of obsessive-compulsive disorder (OCD). METHOD Twenty-nine subjects diagnosed with OCD according to Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria were recruited through the Anxiety Clinic of Louis-H Lafontaine Hospital. They were evaluated at baseline and after treatment on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) by a psychiatrist who was blind to treatment modality. Subjects rated their degree of resistance to their rituals and the strength of their obsessional beliefs. Subjects then received 1 of 4 treatments: medication and CBT simultaneously (n = 9), CBT only (n = 6), medication while on a wait-list for CBT (n = 6), or no treatment while on a wait-list for CBT (n = 5). RESULTS Multivariate analysis revealed that Y-BOCS scores and clinical ratings significantly improved posttreatment in all groups except the nontreatment wait-list control group. Subjects in the 2 active treatment groups receiving CBT showed reduced strength in their obsessional beliefs. The subsequent administration of CBT to those groups on the wait-list also decreased the strength of their primary obsessional beliefs and beliefs about the consequences of not performing the rituals. CONCLUSIONS Our results suggest that either CBT or medication alone is more effective than no treatment. The combination of CBT and medication seems to potentiate treatment efficacy, and we found it more clinically beneficial to introduce CBT after a period of medication rather than to start both therapies simultaneously.