The findings of this study highlight disparities in substance use among youth based on sexual orientation, with some evidence of elevated risk among bisexual adolescents. These results are generally consistent with prior research indicating that both distal and proximal minority stressors—such as discrimination, stigma, and identity‐based exclusion—can accumulate over time and contribute to increased substance use in adolescence. ¹⁰ , ²¹ , ²² However, these disparities were not uniformly observed across all sexual minority subgroups or developmental stages. Patterns of disparity differed across sexual orientation, substance type, and developmental stage rather than uniformly escalating with age. For bisexual youth, disparities in tobacco and marijuana use became more pronounced in late adolescence (16–17 years). In contrast, gay/lesbian youth exhibited the strongest disparity in alcohol use at ages 12–13, while for tobacco use, heterosexual youth reported higher prevalence in early and mid‐adolescence. These findings suggest that substance use disparities among sexual minority youth emerge at different ages and vary in direction and magnitude depending on the substance, highlighting the importance of considering both developmental stage and substance type when evaluating inequities. ³ In models stratified by sex (not controlling for age), bisexual females demonstrated significantly higher odds of tobacco and marijuana use compared to their heterosexual peers, and bisexual males showed elevated odds of tobacco use. However, in models stratified by age and adjusted for sex, disparities among bisexual youth were only statistically significant for tobacco and marijuana use among 16–17‐year‐olds. Among younger adolescents, particularly those aged 12–13, the largest disparity in substance use was observed in alcohol use among gay and lesbian youth. This pattern highlights the need to consider how substance use disparities may emerge or shift based on both age and sexual orientation subgroup, with some differences potentially reflecting developmental timing of risk exposure.

Literature consistently shows higher rates of substance use for individuals who identify as bisexual, compared to those who identify as lesbian/gay or heterosexual. ²³ The increased risk for tobacco use among bisexual females aligns with previous findings that bisexual women report earlier cigarette use initiation, for example, compared to other sexual minority groups. ²⁴ In contrast, bisexual males demonstrated elevated odds of tobacco use but not alcohol or marijuana use, suggesting potential differences in coping mechanisms and risk factors across gender. The increased risk for alcohol use among bisexual females aligns with previous research indicating that bisexual women typically report greater levels of alcohol use and heavy drinking. ²⁵

The unique experiences of bisexual adolescents, often referred to as binegativity, may be exacerbating the disparities observed in the differences by sex and age. Bisexual youth can encounter negative attitudes from both heterosexual and gay/lesbian individuals, leading to uniquely elevated minority stress. ²⁶ This hostility can make it challenging for bisexual individuals to find a safe and supportive community, increasing their risk for psychological distress and unhealthy coping behaviors that include substance use. Future research examining unique stressors experienced by bisexual youth (e.g., binegativity, bisexual invisibility) is recommended.

Interestingly, we did not observe significant differences in substance use across sexual orientation for 14–15‐year‐olds. This may reflect a developmental transition period where identity awareness is increasing, but behavioral health disparities have not yet fully emerged. Alternatively, it may reflect variability in disclosure or misclassification of identity at this age. Prior research has found that bisexual college‐aged women experience disproportionately poorer mental health outcomes than both their lesbian and heterosexual counterparts, including higher levels of anxiety, depressive symptoms, anger, self‐injury, and suicidal ideation. ²¹ This study extends these findings to younger bisexual females (16–17 years), showing that they also experience heightened substance use risks compared to their peers. The cumulative effects of binegativity and elevated minority stress may be placing bisexual adolescent females in a particularly vulnerable position as they progress through adolescence, underscoring the need for targeted interventions that address both structural stigma and mental health disparities. ²⁷

Research indicates that fostering identity‐safe environments through social support and inclusivity programs can help mitigate substance use risks among youth navigating identity uncertainty. ²⁸ School‐based interventions such as Gay‐Straight Alliances have been shown to reduce minority stress and lower substance use behaviors among sexual minority adolescents by fostering a sense of belonging and safety. ²⁹ , ³⁰ Additionally, family‐affirming interventions, such as the Family Acceptance Project, have been linked to reduced substance use and improved mental health outcomes in LGBTQ+ individuals by addressing familial rejection and promoting supportive relationships. ³¹ , ³²

Youth identifying as “other” or “not sure” about their sexual orientation also exhibited substance use disparities, though findings were more variable. Previous research suggests that the absence of a “something else” response option in national surveys may lead respondents to select categories that do not fully reflect their identities, potentially impacting health estimates. ³³ These findings underscore the need for further investigation into the unique experiences of youth in these categories and the role of support networks in promoting resilience and reducing substance use risk. Future research is warranted into how to better capture a wider and more inclusive range of sexual identities in surveillance surveys to investigate the nuances of complex sexual orientations and associated risks for substance use and mental health outcomes.

These findings have important public health implications. Prevention and intervention efforts should incorporate age‐specific and gender‐sensitive approaches to address the unique stressors faced by sexual minority youth. School‐based programs that foster supportive environments, promote mental health resources, and reduce stigma may be particularly effective in mitigating substance use risk. ³⁴ Additionally, ensuring access to identity‐affirming health care and peer support networks may help reduce substance use among youth who identify as “other” or are uncertain about their sexual orientation. ²⁸

This study was not without limitations. First, due to the cross‐sectional nature of the NSDUH data, we cannot establish any causal relationships. Second, the NSDUH does not assess gender identity (i.e., transgender, cisgender), and future research should examine differences by gender identity, as previous research has indicated that significant substance use disparities exist between these groups. ³⁵ Third, the NSDUH data is limited to civilian and noninstitutionalized populations, and results should not be generalized to groups not sampled. Finally, the omission of age adjustment in the sex‐stratified models likely improved model stability, but may have introduced residual confounding by age, leading to inflated effect sizes.

Future research should explore longitudinal trends in substance use disparities among sexual minority youth and examine the role of protective factors such as family support and community engagement. Further investigation is also needed to understand the specific experiences of youth who identify as “other” or “not sure,” as their substance use patterns were more variable. In addition, disaggregated analyses by both age and sex are critical for accurately identifying the timing and nature of disparities across subgroups.