ORIGINAL PAPER Using Information Technology to Evaluate the Detection of Co-Occurring Substance Use Disorders Amongst Patients in a State Mental Health System: Implications for Co-Occurring Disorder State Initiatives Frederick Y. Huang Æ Douglas M. Ziedonis Æ Hsou Mei Hu Æ Anna Kline Received: 11 October 2006 / Accepted: 12 July 2007 / Published online: 10 August 2007 Ó Springer Science+Business Media, LLC 2007 Abstract The current study describes a system-wide method of evaluating detection strategies for co-occurring disorders within a state mental health system. Information technology was used to merge administrative datasets from the New Jersey mental health and substance abuse systems and identify individuals treated in both systems. We measured a 53% detection rate of substance use disorders amongst adult patients in the mental health system with particularly low detection rates in acute settings (49.0%) and among female (43.7%), older (36.2%), and psychotic patients (43.6%). The methodology described here could help evaluate critical aspects of ongoing state co-occurring disorder quality improvement initiatives. Keywords Co-occurring disorder  Detection  Mental illness  Substance abuse This paper was presented at the 2005 American Psychiatric Association Annual Meeting (May 21–26, 2005) in Atlanta, Georgia. F. Y. Huang (&) Department of Psychiatry, University of California, San Francisco, 1001 Potrero Ave., Suite 7M, San Francisco, CA 94110, USA e-mail: Frederick.huang@ucsf.edu D. M. Ziedonis Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, USA H. M. Hu Clinical Information Decision Support Services, University of Michigan Health System, Ann Arbor, MI, USA A. Kline Department of Veterans Affairs, New Jersey Health Care System, Lyons, NJ, USA 123 Community Ment Health J (2008) 44:11–27 DOI 10.1007/s10597-007-9102-y