Tri-ethnic variations of co-morbid substance and alcohol use disorders in schizophrenia

OBJECTIVES: This study examined the differential prevalence of substance and alcohol use disorders among European Americans, African Americans, and Latinos with schizophrenia (n = 6424) who received public mental health services in San Diego County during fiscal year 2002-2003. METHODS: Data were obtained from the public mental health database used by the San Diego County Mental Health System. Chi-Square analyses and stepwise logistic regression analyses were used to examine differences regarding the prevalence of substance and alcohol use among clients with schizophrenia and schizoaffective disorder, and to analyze the sociodemographic variables associated with this co-morbidity. RESULTS: Significant differences in the prevalence of diagnosed co-morbidity were found across the ethnic groups. Rates of co-morbid diagnosis among African Americans (25%) were significantly higher than those among European Americans (22%) and Latinos (19%). Logistic regression results revealed ethnicity was a significant predictor of co-morbid substance and alcohol use, as was being homeless and male. Among Latinos, language preference was also a significant predictor. Latinos who denoted English as their primary language were 1.7 times more likely to be diagnosed with co-morbid substance or alcohol use disorders than Latinos who denoted Spanish. CONCLUSIONS: Among people with schizophrenia, there were significant differences in prevalence rates and predictors of diagnosed co-morbid substance and alcohol use disorders. Future research is needed to examine the relationship among language preference, level of acculturation, and subsequent diagnosing barriers for Latinos. Among African Americans, the reasons behind increased co-morbidity rates need to be examined, and homelessness should be carefully addressed among all three ethnic groups.