Self-reported changes in drug and alcohol use after becoming homeless.

Objectives: We identified substance use patterns and factors associated with increased substance use after users become homeless.

Methods: We carried out a 2-city, community-based survey that used population-proportionate sampling of 91 sites with random selection at each site.

Results: Five hundred thirty-one adults were interviewed; 78.3% of them met Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria for substance abuse or dependence. Most of those who met the criteria reported using drugs and alcohol less since they became homeless, commonly because they were in recovery. Factors independently associated with increased use were no health insurance (odds ratio [OR] = 1.6; 95% confidence interval [CI] = 1.02, 2.58), alcohol abuse or dependence (OR = 3.5; 95% CI = 1.85, 6.78), and selling plasma (OR = 2.6; 95% CI = 1.32, 5.14) or panhandling (OR = 3.0; 95% CI = 1.65, 5.55) to acquire drugs.

Conclusions: Becoming homeless plays a role in self-reported substance use. Multiservice treatment programs and tailored interventions for homeless persons are needed.