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.