Injunctive substance use norms among substance-naïve youth in the United States: Differences by sexual identity and sex assigned at birth

BACKGROUND: Sexual minority (SM) youth are more likely than heterosexual youth to engage in substance use. Injunctive norms, or perceptions of others' substance use attitudes, contribute to youth substance use initiation and progression. METHODS: Among substance-naïve youth (ages 12-17; N = 7628) in the 2023 National Survey on Drug Use and Health, we examined differences in perceived parental, close friend, and personal disapproval of cigarette smoking, marijuana experimentation, monthly marijuana use, and near-daily alcohol use across five sexual identity groups (heterosexual, gay, bisexual, different term, unsure) and sex assigned at birth. RESULTS: Across groups and substances, youth perceived the highest substance use disapproval from parents (range = 72.4% - 97.4%), followed by personal disapproval (range = 52.1% - 87.7%) and disapproval by close friends (range = 48.6% - 81.6%). In multivariable models, bisexual, different term, and unsure youth reported lower close friend (IRR range = 0.89-0.97) and personal (IRR range = 0.89-0.92) disapproval, compared to heterosexual youth. SM females reported lower close friend and personal disapproval than heterosexual females. CONCLUSIONS: SM youth perceive more permissive norms towards substance use. Prevention strategies addressing peer norms and personal permissiveness may be critical for addressing SM youth substance use inequities.