Association of Substance Use Patterns with Psychiatric Disorders in Homeless Persons with Psychiatric Disorders in Vancouver

Substance use and psychiatric disorders are highly prevalent in persons experiencing homelessness. We aimed to investigate the associations between the patterns of substance use and risk behaviors with specific psychiatric disorders in homeless persons with psychiatric disorders using baseline data of the Vancouver sample ( N = 494) of the At Home/Chez Soi study. Psychiatric disorders were diagnosed with the MINI Neuropsychiatric Interview 6.0, and substance use was assessed with the Maudsley Addiction Profile. In a multivariate analysis, major depressive disorder was associated with the use of stimulants and benzodiazepines, respectively. Posttraumatic stress disorder (PTSD) was associated with stimulant use. Panic disorder was associated with alcohol and benzodiazepine use, respectively. Opioid use was less common in participants with a psychotic disorder. Injection use of drugs occurred more often among participants with major depressive disorder, PTSD, and mood disorder with psychotic features. Awareness of these associations will be useful for clinicians for targeted prevention, diagnosis, and treatment of this population.