Co-occurring severe mental illness and substance use disorders: A review of recent research

Objective: Understanding the complex diagnostic and treatment issues posed by the co-occurrence of severe mental illness and substance use disorders has become a necessary exercise in current psychiatric practice. The authors reviewed research studies from the past six years that have contributed to our knowledge about effective assessment, diagnosis, course of illness, and treatment approaches. Research on special populations, including women, persons infected with HIV, and violent patients, is highlighted. Methods: PsycINFO, Silver Platter, and MEDLINE were used to search for English-language studies published in the United States and other countries. To augment the search, selected bibliographies were reviewed with a focus on clinical standards. Information was sought on epidemiology, screening and assessment strategies, course of illness, models of treatment delivery, and cost of care. Results and conclusions: Although estimates of the prevalence of substance use disorders vary by population, a higher prevalence among persons with severe mental illness has been confirmed. Routine screening for and assessment of substance use disorders among persons with severe mental illness has become the accepted standard of care. The course of severe mental illness is negatively influenced by a substance use disorder, and an integrated approach to the treatment of both disorders is generally accepted to be the most promising treatment strategy. Components of this strategy include harm reduction, treatment in stages, motivational interviewing, cognitive-behavioral interventions, and modified 12-step self-help groups.