CLINICAL HANDBOOK OF SCHIZOPHRENIA

412 VI. SPECIAL POPULATIONS AND PROBLEMScuss what is known about the effectiveness of various interventions and service approaches.Finally, we propose broad treatment guidelines based on the available data, incombination with our clinical experience.HOW COMMON IS HOMELESSNESS AMONG PEOPLEWITH SEVERE MENTAL ILLNESS AND SCHIZOPHRENIA?Methodological difficulties, chiefly varying definitions of homelessness and the frequentreliance on small, unrepresentative samples of mentally ill persons, have limited the reliabilityof many estimates of the occurrence of homelessness in the mentally ill population.However, several methodologically rigorous studies confirm that the prevalence of homelessnessin persons with SMI, including schizophrenia, is distressingly high. For instance,in a study of patients admitted to a state hospital in New York, 28% of those diagnosedwith schizophrenia spectrum disorders reported that they had experienced homelessnessduring the 3 years preceding the current hospitalization (Susser, Lin, & Conover, 1991a).In a study of persons with schizophrenia spectrum disorders who were discharged frominpatient psychiatric treatment in New York City, roughly 8% of subjects reported atleast one episode of homelessness during the 3 months following discharge, a proportionthat is likely an underestimate because of significant loss to follow-up (Olfson, Mechanic,Hansell, Boyer, & Walkup, 1999).One of the most recent major studies used administrative data to estimate the periodprevalence of homelessness among all service users of the public mental health system inSan Diego. This study found that roughly 15% of patients with schizophrenia experiencedhomelessness over the course of 1 year (Folsom et al., 2005). This estimate is notinconsistent with the results from an earlier study of persons treated in the public mentalhealth system in Philadelphia, in which 10% of persons with SMI had used the publicshelter system during a 3-year period (Culhane, Averyt, & Hadley, 1997).The elevated risk of homelessness in persons with schizophrenia and other severemental disorders is not limited to those who have long histories of involvement in themental health services system. For instance, in a suburban county, a study of a representativesample of persons hospitalized for the first time with psychotic disorders (includingbut not limited to schizophrenia spectrum disorders), found that 15% had experienced atleast one lifetime episode of homelessness before or within 2 years of their initial hospitalization,and that a majority of these episodes occurred before the initial hospital stay(Herman, Susser, Jandorf, Lavelle, & Bromet, 1998).HOW COMMON IS SCHIZOPHRENIAAMONG PERSONS WHO ARE HOMELESS?This is perhaps the most commonly asked and frequently studied question pertaining tothe nexus of homelessness and mental disorder. Nevertheless, the usefulness of manystudies of this issue has been limited by both nonrepresentative sampling schemes andnonstandard diagnostic ascertainment. In addition, because it has been shown that SMI israre among homeless persons who are housed as families (one of the fastest growinghomeless subgroups), prevalence studies that include homeless families necessarily generatesystematically lower estimates of SMI.A comprehensive review of this question summarized the results of 10 studies thatemployed rigorous diagnostic and sampling methods to estimate the prevalence of schizo-