摘要：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. Homelessness is associated with premature mortality and high levels of morbidity, 1– 3 despite the fact that homeless persons utilize health care systems at very high rates. 4– 7 Much of this high rate of use has been attributed to substance abuse, 8, 9 which, in a study of homeless persons in Alameda County, California, was reported to be 8 times more prevalent among the homeless than among the general population. 10 Also in this study, more than half (52.4%) of homeless respondents had a current substance use disorder. Current drug disorders were more common among respondents who were younger and who had been homeless longer. Whereas in the general population low educational attainment, unemployment, and marital status are associated with substance use, homelessness and recent institutionalization have been identified as significant factors in substance use among homeless persons. 11 However, we know much less about the relationship between homelessness and substance abuse than we do about the incidence or prevalence of substance abuse disorders among homeless persons. What effect does homelessness have on the amount of drugs and alcohol being consumed? How is a drug addiction supported in the context of the extreme poverty associated with being homeless? What are the individual and societal costs of addiction among the homeless? Models attempting to define the relationship between substance abuse and homelessness have noted a bidirectional relationship, with both social selection and social adaptation taking place. 12 Substance abuse has been linked indirectly to actual loss of housing but linked directly to a breakdown of social bonds, 13 whereas chronic homelessness has been associated with an earlier age at onset of drug and alcohol use disorders. 14 An appreciation of the dynamics and causative factors associated with homeless is necessary if we are to develop better-informed public policies and medical and social interventions. In this article we present data from a 2-city, community-based study of urban homeless adults that describes the effects of self-reported trends and patterns of substance use on homeless status, means of acquiring drugs and supporting an addiction, and interactions with the criminal justice system. Our hypothesis in this study was that drug and alcohol use would increase once a person became homeless, reflecting the increased stresses and social isolation of being homeless and the role of substance abuse in causing homelessness.
