Comorbidity of obsessive compulsive disorder in bipolar disorder.

The comorbidity of OCD and bipolar disorder has not been systematically examined. Therefore, we determined the frequency of patients meeting DSM-III criteria for OCD syndrome in a sample of 149 inpatients with DSM-III major affective disorder who had received a clinically reviewed structured diagnostic interview. The frequency of OCD syndrome was not significantly different between subjects with major depression (35.2%, n = 105) and bipolar disorder (35.1%, n = 37). This suggests that OCD is equally common in bipolar as in unipolar patients.