CLINICAL HANDBOOK OF SCHIZOPHRENIA

40. Housing Instability and Homelessness 413phrenia in homeless persons, including research carried out in the United States and elsewhere(Folsom & Jeste, 2002). The overall prevalence of schizophrenia among the stringentlydesigned studies ranged between 4 and 16%, with a weighted average prevalenceof 11%. This, the authors note, is roughly 7–10 times higher than the prevalence ofschizophrenia in the U.S. housed population. Schizophrenia tended to be more commonin younger persons; in the chronically homeless; and single homeless women, who wereabout twice as likely as men to be diagnosed with schizophrenia.WHAT INDIVIDUAL-LEVEL FACTORS ARE ASSOCIATEDWITH HOMELESSNESS AMONG PEOPLEWITH SEVERE MENTAL ILLNESS?What do we know amount about particular demographic, clinical, and life-history factorsassociated with homelessness in people with schizophrenia? Do those who becomehomeless have more severe disorders than their domiciled counterparts? Do they havemore comorbid disorders, such as substance misuse, antisocial personality, and seriousmedical conditions? Are they less “adherent” to treatment? Do they have less family support?Have they had adverse childhood experiences that predispose them to adult homelessness?A number of studies have shed light on these questions.Comorbid substance abuse appears to be an important factor associated with homelessnessamong persons with schizophrenia and other severe mental disorders. A case–control study of homeless versus never-homeless men with schizophrenia found that aconcurrent diagnosis of drug abuse (but not alcohol abuse) was significantly associatedwith homelessness, whereas a companion study of women with schizophrenia found thatboth drug and alcohol abuse were risk factors for homelessness. The association betweenhomelessness and substance abuse in severely mentally ill persons has also been found ina number of other methodologically rigorous studies, with drug abuse tending to be morestrongly associated with homelessness than alcohol abuse (Caton et al., 1994, 1995).Adverse childhood experiences such as family separations, abuse, and neglect havebeen shown to be potent risk factors for homelessness in the general population and havealso been found to be associated with homelessness in persons with SMI. Perhaps thelargest study of this question to date compared the prevalence of childhood adversities inseverely mentally ill homeless persons and a comparison group of never-homeless psychiatricpatients, and found that histories of out-of-home care and running away from homewere significantly more common in the homeless group (Susser, Lin, Conover, &Struening, 1991b). Consistent with this finding, the previously mentioned Caton and colleagues(1994) study of men with schizophrenia found that the level of family disorganizationduring childhood (as measured by a composite scale) was significantly higher inthe homeless group compared with the never-homeless comparison group. There is someevidence that, particularly among women with SMI, lack of current family support is associatedwith homelessness.As in studies of the general population, race appears to be associated with the risk ofhomelessness among persons with severe mental disorders. The recent San Diego studywe noted earlier found that African American with SMI were somewhat more likely toexperience homelessness than their European American, Latino, and Asian Americancounterparts.Homeless mentally ill persons are likely to suffer from serious, and often neglected,medical conditions. Homeless people are especially at risk for tuberculosis, HIV, asthma,pneumonia, bronchitis, hypertension, diabetes, and circulatory and vascular disorders.