A review of treatments for people with severe mental illnesses and co-occurring substance use disorders.

Several interventions for people with co-occurring severe mental illnesses and substance use disorders have emerged since the early 1980s. This paper reviews 26 controlled studies of psychosocial interventions published or reported in the last 10 years (1994-2003). Though most studies have methodological weaknesses, the cumulative evidence from experimental and quasi-experimental research supports integrating outpatient mental health and substance abuse treatments into a single, cohesive package. Effective treatments are also individualized to address personal factors and stage of motivation, e.g., engaging people in services, helping them to develop motivation, and helping them to develop skills and supports for recovery. Accumulating evidence from quasi-experimental studies also suggests that integrated residential treatment, especially long-term (one year or more) treatment, is helpful for individuals who do not respond to outpatient dual disorders interventions. Current research aims to refine and test individual components and combinations of integrated treatments.