Substance abuse and the chronically mentally ill: a description of dual diagnosis treatment services in a psychiatric hospital.

Between 20% and 70% of psychiatric patients have a co-occurring substance use disorder and rates of substance abuse among patients with psychotic disorders are especially high. Patients with co-existing psychosis and substance use disorders typically have poorer outcomes than patients diagnosed with either disorder alone. Frequently, treatment services for such dually diagnosed patients are not integrated and organizational barriers may impede the appropriate detection, referral, and treatment of these patients. This article reviews the epidemiology and treatment outcome for patients dually diagnosed with chronic mental illness (usually psychotic disorders) and substance use disorders. The article then presents a description of a dual diagnosis referral and treatment service in a large private, non-profit psychiatric hospital.