The present analyses utilized the largest known sample of systematically assessed subjects with SC from the Latino population, drawn from the NIMH Genetics of Schizophrenia in Latino Populations study, to estimate the frequency of DD in the subjects in this study. In addition, the present study describes the clinical characteristics of subjects with comorbid SUD in these Latino subjects and compares rates of DD across three geographic regions (the Southwest United States, Mexico, and Central America). We also tested several hypotheses regarding SUD comorbidity in SC subjects within this sample. These hypotheses included that SUD comorbidity would be higher in the US subjects compared to those from Mexico and Central America and that rates of comorbidity would be, in general, less than previous studies of SC in non-Latino populations. Based on studies conducted in other samples (Bartels et al., 1993; Menezes et al., 1996; Soyka et al., 2001; Swartz et al., 2006; Weaver et al., 1999), we also hypothesized that gender, marital status, employment status, and immigration to the US from Mexico would be associated with comorbidity in this sample.
