Risk of polysubstance use among sexual minority and heterosexual youth

Background: Relative to heterosexual youth, sexual minority youth exhibit increased substance use. Risk for polysubstance use, which magnifies drug-related harms, remains largely unexamined for sexual minority youth. This investigation used a nationally-representative dataset to compare polysubstance use patterns between sexual minority and heterosexual youth. Methods: The cross-sectional 2015 CDC's Youth Risk Behavior Surveillance System (N = 15,624) was utilized. Latent mixture modeling empirically identified subgroups of youth based on self-reported past-month use of alcohol, cigarettes, chewing tobacco/snus/snuff, cigars/cigarillos/little cigars, e-cigarettes, marijuana, and pastmonth binge drinking (all dichotomized: 0 = none; 1 = at least once). Adjusting for race/ethnicity, sex, and age, the risk for being in each substance-using class, was compared between youth who self-identified as heterosexual and gay/lesbian, bisexual, or "not sure." Results: Five classes were supported: "non-users" (68.19%), "alcohol users" (13.08%; elevated alcohol use and binge drinking probabilities), "nicotine/marijuana co-users" (5.80%; elevated nicotine and marijuana use), "poly-substance/e-cigarette users" (5.35%; elevated on all substances except tobacco-containing products), and "polysubstance/tobacco users" (7.59%; elevated for all substances). Relative to heterosexual youth, gay/lesbianidentified youth were at risk of being "nicotine and marijuana co-users", bisexual youth were at risk of being in all four substance-using classes, and the "not sure" youth were at risk of being "polysubstance/tobacco users." Select disparities were larger for youth who were also female or a minority race/ethnicity. Conclusions: Sexual minority youth, particularly bisexual youth, were at increased risk relative to heterosexual youth for polysubstance use. Polysubstance use warrants attention in substance use interventions, including interventions tailored for sexual minority youth.