The influence of co-occurring axis I disorders on treatment utilization and outcome in homeless patients with substance use disorders.

The current study examined the relationship between co-occurring substance use and Axis I psychiatric disorders and treatment utilization and outcome among homeless individuals (N=365) who participated in an episode of intensive outpatient substance use treatment. Compared to patients without a co-occurring diagnosis, homeless patients with a diagnosis of major depressive disorder or PTSD participated in more substance use treatment. Diagnostic status did not predict 12-month alcohol or drug treatment outcome. Substance use treatment programs appear to successfully engage homeless individuals with major depressive disorder and PTSD in treatment. Such individuals appear to achieve similar benefits from standard substance use treatment as do homeless individuals without such disorders.