P SYCHOPHARMACOLOGY B ULLETIN: Vol. 39 · No. 1 • 25 Reliability and Validity of the Yale-Brown Obsessive-Compulsive Scale in Schizophrenia Patients By Lieuwe de Haan, MD, PhD, Britt Hoogeboom, MD, Nico Beuk, MD, Luuk Wouters, Peter M.A.J. Dingemans, PhD, and Don H. Linszen, MD, PhD Dr. De Haan is senior consultant at the Adolescent Clinic, Academic Medical Center, Amsterdam, The Netherlands. Dr. Hoogeboom is resident at Mentrum Mental Health, Amsterdam. Dr. Beuk is resident in University Medical Center, Utrecht. Dr. Wouters is research psychologist, statistical con- sultant, Academic Medical Center, Amsterdam. Dr. Dingemans is clinical and research psychologist, Academic Medical Center, Amsterdam. Dr. Linszen is Professor of Psychiatry and Head of the Adolescent Clinic, Academic Medical Center. To whom correspondence should be addressed: Dr. L. de Haan, Academic Medical Center, University of Amsterdam, Department of Psychiatry, Postbox 22700, 1100 DE Amsterdam, The Netherlands; Tel.: + 31 20 5662210; Fax : + 31 20 6919139; E-mail: l.dehaan@amc.uva.nl ABSTRACT ~ 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. Psychopharmacology Bulletin. 2006;39(1):25-30. Key Words: psychometric evaluation, obsessive-compulsive disorder, co-morbidity, assessment ORIGINAL RESEARCH INTRODUCTION A growing literature suggesting that obsessive-compulsive symptoms (OCS) occur in 7.8% to 46% 1-10 of patients with schizophrenia has prompted renewed interest in this issue by clinicians and researchers. The severity of OCS is often assessed with the Yale-Brown Obsessive- Compulsive Scale (Y-BOCS). 11 The Y-BOCS, a semistructured interview, was introduced by Goodman and colleagues 11,12 to measure OCS in a content-free format in patients with obsessive- compulsive disorder (OCD). The scale ratings do not depend on specific types of symptoms but are instead based on aspects of those symptoms as reported by the patient during the interview (eg, duration, interference, degree of resistance). The 025-030_PB_V39N1_de_Haan.qxd 9/21/06 5:35 PM Page 25