Community-based Programs for Homeless Adults with Concurrent Disorders: “What Works for Whom, Where, Why and How?”

A summary report on the effectiveness of community services for homeless adults with concurrent mental health and substance use disorders.

The purpose of this report is to guide policy development and appropriate program investment and implementation to address concurrent disorders (CD) in homeless populations.

North American estimates suggest that as many as 10-20% of homeless adults experience concurrent mental health and substance use disorders. However, referral options and services for CD are often limited, and homeless clients face multiple barriers to receiving and benefiting from care.

In Toronto, Canada, a partnership of community-based agencies and researchers identified the need for strong evidence to guide decision-making related to CD services.

An evidence synthesis was conducted, based on a search of post-1980 English language publications in social sciences and health sciences research databases. Altogether, we collected evaluations of 10 different community programs for homeless clients with CD. Information from academic articles was supplemented with program information collected online and through interviews with authors of the articles.

In reviewing the evidence, we asked not only, “what works” to address mental health and substance use disorders in homeless clients. We also explored the underlying mechanisms of CD programs, and asked, “how do successful programs work?; for whom do they work?; under what circumstances?; and why?”