Treatment
Historically, the mental health and substance abuse treatment systems in the United States have been separate, and
traditional approaches to treating people with co-occurring disorders have involved parallel
or sequential treatment in these separate systems. In practice, patients with co-occurring mental and substance
use disorders have rarely received needed treatments and have generally experienced poor outcomes.
As a result, there has been widespread endorsement by patients, clinicians, administrators, and researchers for integrating mental health and substanceabuse services.
There is also accumulating research support for the effectiveness of the integrated treatment approaches that
have evolved over the past two decades.