Substance use among sexual minorities in the US – Linked to inequalities and unmet need for mental health treatment? Results from the National Survey on Drug Use and Health (NSDUH)

Background A social group found to be particularly burdened by disparities in substance use is the group of sexual minorities (SM). We investigated the potential association between substance use among SM adults in the United States (US) and social inequality, with an additional focus on disparities in unmet need for mental health treatment. Methods A secondary cross-sectional data analysis was performed using National Survey on Drug Use and Health (NSDUH) data from 2015 to 2017 and including 126,463 individuals with 8,241 identifying as SM. Multivariable logistic regression models were implemented to quantify disparities in substance use, to calculate the effect of sociodemographic variables on substance use, and to examine associations to socioeconomic vulnerability. Findings SM showed higher odds of past-year substance use and lifetime chemsex drugs use. All SM except for bisexual men exhibited higher odds of past-month binge drinking relative to heterosexuals. Bisexual women had higher odds for use of all analysed substances relative to heterosexual women. Being older and being a woman were shown to be protective factors. Urbanity, being uninsured, and unmet need for mental health treatment were associated with significantly higher odds of substance use, chemsex drugs use and binge drinking. A link was established between drug use and health, with higher odds of drug use for lower health ratings. SM experienced significantly higher levels of socioeconomic vulnerability. Higher vulnerability indices were associated with increased odds for drug use. Interpretation This study is among the first nationally representative samples that analysed the effect of sociodemographic determinants and unmet need for mental health treatment on substance use in SM. It emphasises the multifactorial aetiology of vulnerability to substance use and highlights the distinct disparities in, and underlying mechanisms for substance use among SM. Approaches tailored to SM subgroups may be needed to address the problems of increased substance use for this population in the long-term. However, critical gaps in the literature remain and large-scale studies inclusive of SM individuals are needed to present causal links. Funding: Gillings Fellowship SYOG054 to ARU