Sex differences in psychosocial correlates of concurrent substance use among heterosexual, homosexual and bisexual college students.

BACKGROUND: College students identifying as Lesbian, Gay or Bisexual (LGB) are at increased risk for substance use. Few studies have assessed correlates of concurrent substance use, which increases the risk for substance use disorders.
OBJECTIVES: The current study aimed to (1) examine differences in substance use among male and female sexual minorities and (2) explore the impact of psychosocial factors on the relationship between sexual identity and concurrent substance use.
METHODS: A web-based survey assessing health behavior, psychosocial characteristics, attitudes and demographics was administered to students from six colleges in the southeastern US. A total of 4840 students responded to the survey; 2.9% reported a homosexual identity (n = 111) and 3.5% reported a bisexual identity (n = 135). Multivariable modeling was used to assess the relationship between sexual identity and the number of substances used, adjusting for demographic and psychosocial factors.
RESULTS: Bisexual females were significantly more likely than their homosexual or heterosexual counterparts to report tobacco use (p < 0.0001), binge drinking (p < 0.05) and marijuana use (p < 0.0001) in the past 30 days. No differences in substances used existed among males. Adjusted for age and ethnicity, homosexually- and bisexually-identified females were more likely to have concurrent substance use than those who identified as heterosexual (p < 0.0001 and p < 0.0001, respectively). Adjusting for psychosocial factors decreased the magnitude and significance of the association (p < 0.01 and p < 0.001, respectively).
CONCLUSION: Female sexual minorities are at high risk for substance use. Targeting specific psychosocial factors might be useful in efforts to address use of tobacco, alcohol and marijuana among LGB young adults.