Co-occurring mental and substance use disorders: promising approaches and research issues.

This paper surveys the mental health and drug user treatment literature, identifying promising approaches and research issues in the treatment of co-occurring mental illness and substance use disorders. The prevalence and classification of co-occurring disorders are briefly reviewed, and selected treatment models currently in use are described. Three models are cited as representing particularly promising approaches--comprehensive integrated treatment, assertive community treatment, and the modified therapeutic community--and best practices are summarized. This paper proposes a research agenda focused on relevant emerging treatment issues.