Ethnic/racial differences in substance use and mental health morbidity in the California Quality of Life Surveys

Background: Lesbian, gay, and bisexual adults are at elevated risk for mental health and substance use disorders due in part to anti-gay stigma (Cochran & Mays, 2009). Little of this work (Cochran et al., 2007; Meyer et al., 2007), however, has examined whether there is greater excess risk among LGB ethnic/racial minorities who face dual sources of possible discrimination. Objectives: We investigate possible interactions between sexual orientation and ethnicity/race in mental health and substance use morbidity to examine evidence for additive and/or multiplicative effects of discrimination. Methods: The Cal-QOL I/II surveys drew population-based samples of Californians, age 18 to 72 years, with oversampling for minority sexual orientation (combined N=5087). All were administered a structured interview assessing sexual orientation and CIDI-SF-based past year mental health and substance use morbidity. Multivariate logistic regression methods were used to examine the effects of ethnicity/race and sexual orientation in predicting prevalence of disorders after adjusting for possible demographic confounding. Results: As anticipated, LGB individuals evidenced greater 1 year prevalence for all 5 measured disorders (marginal prevalence for meeting criteria for at least 1 of 5 disorders=37.0%, SE=3.0%) as compared to heterosexuals(24.0%, SE=1.0%). We observed 1 significant interaction between ethnicity/race and sexual orientation. Specifically, although Asian American heterosexuals were least likely to meet criteria for depression (6.0%, SE=2.0%), LGB Asian Americans were most likely to (45.0%, SE=10.0%). In addition, consistent with the research literature, we observed among heterosexuals that Hispanic, Black, and Asian American individuals were significantly less likely to meet criteria for any of the 5 disorders compared to both Whites and Native Americans. However, this expected ethnic/race effect was not present among LGB persons. Conclusions: Normative ethnic/race differences in mental/substance use disorders prevalence may be attenuated in the LGB population. LGB persons, regardless of ethnicity/race, evidence elevation in morbidity risk compared to heterosexuals.