A national longitudinal study of sexual orientation discordance, sexual identity fluidity, and alcohol and other drug use disorder symptoms.

Many national studies fail to account for discordance between sexual orientation dimensions (e.g. a mismatch between sexual identity and sexual attraction) or sexual identity fluidity (e.g. changes in sexual identity over time). To examine the longitudinal relationships among sexual identity fluidity/stability, sexual orientation discordance/concordance, and alcohol and other drug use disorder symptoms. The study used nationally representative longitudinal data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health (PATH) study of US adolescents and adults ( = 24,591). Substance use disorder symptoms were most prevalent (45.8%) among bisexual-stable females relative to all other sexual identity subgroups. The adjusted odds ratios (AORs) of substance use disorder symptoms were significantly higher among bisexual-stable females vs. heterosexual-stable females in all models (AOR range: 1.94-2.32), while no such associations were found for males. Sexual identity-attraction discordant females had significantly greater AORs (17/20 instances) of substance use disorder symptoms compared to concordant females; this finding was not as consistent for males (6/20 instances). Sexual orientation discordance was significantly associated with substance use disorder symptoms, especially among females discordant in their sexual identity and attraction. Bisexual-stable and discordant females are at highest risk of developing symptomatic substance use; it is vital that they receive screening, no matter where they are in their coming out process. This study highlights pitfalls of relying solely on cross-sectional data using a single sexual orientation dimension to understand the relationship between sexual orientation and substance use disorder.