Substance abuse and mental health disparities: Comparisons across sexual identity groups in a national sample of young Australian women

A growing body of research amply documents health disparities related to substance abuse among sexual minority women. However, relatively little research has examined risk factors or predictors of substance use in this population and even less has explored differences among sexual minority subgroups. Using data from 8850 women aged 25-30 years in the 2003 survey of the Australian Longitudinal Study on Women's Health Survey (ALSWH) we compared rates of substance use (alcohol, marijuana and other illicit drugs) and potential predictors (e.g., depression, anxiety, perceived stress, lower levels of social support) across four sexual identity groups--exclusively heterosexual, mainly heterosexual, bisexual and lesbian. Using statistical weighting of the sample and controlling for demographic characteristics we fitted logistic regression models to estimate adjusted odds ratios for substance use. Compared with exclusively heterosexual women sexual minority women reported significantly higher levels of substance use--but there was notable variation among the three sexual minority subgroups. Women who identified as mainly heterosexual were significantly more likely than exclusively heterosexual women to report at-risk drinking and those who identified as bisexual were more likely to report marijuana use. Mainly heterosexual and bisexual women were also more likely to report binge drinking. Findings implicate stress as an important predictor of substance use and emphasize the need for research that more systematically examines the relationships between minority stress and substance use in sexual minority women. Findings of variations in risk across sexual minority subgroups suggest prevention and intervention strategies aimed at reducing health disparities should be targeted toward specific sexual minority subgroups.