Drug use disorders and treatment contact among homeless adults in Alameda County, California.

OBJECTIVES: This study estimates the extent and distribution of specific drug problems among homeless adults. METHODS: A countywide probability sample of 564 homeless adults received structured interviews that included a standardized assessment of substance use disorders. RESULTS: Two thirds of the sample (69.1%) had a lifetime history of a substance use disorder (including abuse of or dependence on alcohol 52.6% or drugs 52.2%); half had a current (52.4%) substance use disorder (including alcohol 38.8% or drugs 31.3%). Current drug disorders were higher among respondents who were younger, homeless longer, or sampled from the city of Oakland, Calif. Alcohol use disorders were higher among men than among women; surprisingly, drug use disorders were not. CONCLUSION: Rates of current drug use disorders for homeless adults were more than eight times higher than general population estimates. However, estimates of drug problems among homeless adults vary as a function of case ascertainment and sampling strategy. Estimates based only on samples from urban areas may overestimate drug problems among the area's larger homeless populations.