Social networks and sexual orientation disparities in tobacco and alcohol use.

OBJECTIVE The purpose of this study was to examine whether the composition of social networks contributes to sexual orientation disparities in substance use and misuse. METHOD Data were obtained from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative cohort study of adolescents (N = 20,745). Wave 1 collected extensive information about the social networks of participants through peer nomination inventories. RESULTS Same- and both-sex-attracted youths had higher frequency/quantity of tobacco use in their peer networks than did opposite-sex-attracted youths, and both-sex-attracted youths had higher frequency/quantity of alcohol use and misuse in their peer networks than opposite-sex-attracted youths. Among same- and both-sex-attracted youths, greater frequency/quantity of tobacco use in one's social network predicted greater use of cigarettes. In addition, greater frequency/quantity of peers' drinking and drinking to intoxication predicted more alcohol use and alcohol misuse in the both-sex-attracted group. These social network factors mediated sexual orientation-related disparities in tobacco use for both- and same-sex-attracted youths. Moreover, sexual orientation disparities in alcohol misuse were mediated by social network characteristics for the same-sex and both-sex-attracted youths. Importantly, sexual minority adolescents were no more likely to have other sexual minorities in their social networks than were sexual majority youths, ruling out an alternative explanation for our results. CONCLUSIONS These findings highlight the importance of social networks as correlates of substance use behaviors among sexual minority youths and as potential pathways explaining sexual orientation disparities in substance use outcomes.