Reversing a history of unmet needs: approaches to care for persons with co-occurring addictive and mental disorders.

Individuals with co-occurring addictive and mental disorders are particularly vulnerable to negative outcomes. Historically, they have been treated either in mental health or addiction service settings and sometimes excluded from receiving any services at all. This article presents an overview of the prevalence and clinical correlates of co-occurring disorders, and of the historical development of separate care systems for mental and addictive disorders. The articles that follow address future treatment and service system development.