It is also possible that factors associated with identity development as a sexual minority, LY3009104 such as gender expression, may contribute as some sexual-minority women may seek to express a masculine role presentation through smoking and other substance use behaviors (Hahm et al., 2008; Rosario, Schrimshaw, & Hunter, 2008). Future research should test these and other possible mechanisms in studies containing heterosexual and sexual-minority youths recruited through methodologically rigorous sampling strategies (Corliss, Cochran, & Mays, 2009). Our data revealed that youths of all minority sexual orientations were more likely to smoke their first cigarette at younger ages than completely heterosexuals.

Younger age at first smoking accounted for a significant proportion of disparities in subsequent smoking during the adolescent and emerging adulthood periods for mostly heterosexuals and bisexuals of both genders and to a lesser extent for lesbians, but not for gay males. These findings suggest that there may be heterogeneity across sexual-orientation subgroups and gender in the degree that age at initiation contributes to smoking disparities. These findings also indicate that factors other than age at smoking initiation may be more salient in explaining disparities among gay males and lesbians compared with bisexuals and mostly heterosexuals. One possible explanation is that gay men and lesbians may be more involved in the LGB community than bisexuals and mostly heterosexuals and thus have greater exposure to factors within the community that are conducive to smoking such as greater exposure to smokers and social settings where smoking occurs (e.

g., pride events). Lesbians and gay males in GUTS reported greater involvement in the LGB community than bisexuals and mostly heterosexuals, and involvement in LGB social activities was associated with higher risk for drug use (Corliss, Rosario, Wypij, Frazier, & Austin, 2007). It is possible that the influence of identity development as a sexual minority (Rosario, Schrimshaw, & Hunter, 2004) on risk for smoking is larger in lesbian/gay compared with other sexual-minority subgroups. Some limitations should be noted. GUTS is not a representative probability sample and is comprised of mostly non-Hispanic Whites whose mothers have nursing degrees. Thus, generalizability is limited and findings are likely more applicable to White youth from middle-class backgrounds. However, findings with respect to sexual orientation are less biased than findings Brefeldin_A from studies that recruit participants through the LGB community. A possible source of bias is that information is based on self-reports.