Aims
To estimate longitudinal associations between self-reported sexual orientation and past-year polysubstance use among youth, and test how gender, age, and early onset of tobacco and alcohol use contributed to variation in polysubstance use.
Design
Longitudinal community-based cohort of U.S. adolescents from the Growing Up Today Study (GUTS 1) (N=16,873) followed from ages 12–29 years.
Setting
United States of America (USA).
Participants
13,519 individuals (7,839 females; 5,680 males) who responded to at least one of five self-administered questionnaires from 1999–2010. Ninety-three percent reported their race/ethnicity as non-Hispanic white.
Measurements
Multivariable repeated measures generalized estimating equations estimated relative risks (RRs) of concurrent polysubstance use (i.e., past 12-month use of three or more substances) comparing sexual orientation minority youth (i.e., mostly heterosexual [MH], bisexual [BI], gay/lesbian [GL]) to their same-gender, completely heterosexual (CH) counterparts. Mediation analyses tested whether early onset of tobacco and/or alcohol use explained relationships between sexual orientation and concurrent polysubstance use.
Findings
Compared with their same-gender CH peers, sexual minorities evidenced higher risk for concurrent polysubstance use over all repeated measures (RRs for sexual minority subgroups: 1.63–2.91, p-values: <0.001), and for all age groups (RRs: 1.50–4.04, p-values: <0.05-<0.001), except GL males aged 18–20 years. Differences between sexual minorities and CHs were larger among females than males (p-values for sexual-orientation-by-gender interactions were <0.05 for MHs and BIs), and among younger vs. older ages (p-values for sexual-orientation-by-age interactions were <0.05 except for BI males). Sexual minorities’ younger age of smoking and/or drinking initiation contributed to their elevated polysubstance use (% of effect explained was between 9.4–24.3, p-values: 0.04-<0.001), except among GL males.
Conclusions
Sexual minority youth in the USA, and in particular younger females, appear to be at disproportionate risk for concurrent past-year polysubstance use. Early onset of smoking and drinking may contribute to elevated risk of polysubstance use among sexual minorities.