Abstract
Background: Sexual minority youth, especially girls, are at risk for alcohol, cigarette, and marijuana use when these substances are examined individually. However, little is known about concurrent use of these substances (i.e., three-substance use) in relation to sexual orientation. Objectives: The present study compared profiles of past year alcohol, cigarette, and marijuana use between SMGs and heterosexual girls. In addition, because internalizing and externalizing symptoms are associated with substance use, we examined whether sexual orientation was associated with substance use profile over and above co-occurring psychopathology. Methods: Mixture modeling was used to identify patterns of alcohol (including binge drinking), cigarette, and marijuana use in the past year using a cross-sectional sample of urban adolescent girls (Pittsburgh Girls Study; N = 2,064; mean age = 17). Approximately 8% (n = 173) of the girls endorsed a lesbian or bisexual identity. Results: Five substance using classes were identified: low-level substance use (72%), marijuana use (5%), cigarette use (8%), alcohol use (8%), and three-substance use (7%). SMGs were at an increased risk for substance use than heterosexual girls, particularly three-substance use (OR = 6.69, p < .001), cigarette use (OR = 6.26, p < .001), and marijuana use (OR = 3.86, p < .001) classes. Substance use patterns were regressed on sexual orientation, internalizing symptoms (i.e., depression, anxiety), and externalizing symptoms (i.e., conduct problems, oppositional defiant disorder). The disparities remained robust after controlling for internalizing and externalizing symptoms. Conclusions/Importance: Clinicians and researchers should be aware of potential three-substance use among SMGs. Substance use interventions for SMG may benefit from targeting risk factors that cut-across several substances, particularly externalizing symptoms.