Reliability and validity of the Yale-Brown Obsessive-Compulsive Scale in schizophrenia patients.

Although a sizeable minority of people with schizophrenia manifest obsessive and compulsive symptoms, to our knowledge there are no studies of the psychometric performance of measures such as the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The present study examined psychometric properties of the Y-BOCS in patients with recent-onset schizophrenia and comorbid obsessive-compulsive symptoms (OCS). To 37 patients with recent-onset schizophrenia and related disorders and comorbid OCS taken from 135 consecutively admitted patients we administered the Y-BOCS at admission and 6 weeks later. The Y-BOCS showed good internal consistency and interrater reliability in this population; however, findings concerning the divergent validity against depressive and negative symptoms are inconsistent.