Background Evaluate depressive symptoms and substance use among high risk Mexican (MA) and African (AA)-American adolescent women and identify factors associated with substance use to inform development of community-based interventions for high risk adolescents.

Methods AA (n = 94, 16.8%) and MA (n = 465, 83.2%) women (14–18 years) with histories of sexually transmitted infection (STI) or violence and high risk sexual behaviour were recruited from metropolitan public-health clinics. Participants completed semi-structured interviews including assessments for violence, sexual risk behaviour, personal, family, peer, and partner substance use, depressive symptoms, and psychological stressors.

Results Most participants (82%) reported elevated depressive symptoms (Centers for Epidemiologic Studies Depression Scale > 16) which were significantly associated with history of STI (p = 0.049). MA adolescents were more likely than AA adolescents to report high levels of psychological stressors (t = –2.38, p = 0.018), cigarette (74% vs. 52%, p < 0.001), alcohol (79% vs. 60%, p < 0.001), and other drug use (87% vs. 67%, p < 0.001). Substance use was associated with history of STI for MA adolescents only (p = 0.047). Over 79% of participants reported having a partner who used substances. No differences in STI history, depressive symptoms, physical, sexual or emotional violence, or partner substance use were identified by ethnicity. Controlling for theoretically guided variables (i.e., ethnicity, history of violence or STI, sex partners, life stressors, pregnancy), multinomial logistic regression analysis indicated ethnicity, numbers of sexual partner and depressive symptoms were predictors of substance use (X2(6, N = 554) = 53.22, p < 0.001). Participants with substance using partner were more than two times as likely to use substances themselves.

Conclusions Findings suggest interventions aimed at reducing the incidence of STI should include comprehensive protocols that address depressive symptoms and substance use, particularly with MA adolescents. The role of partner substance use is also a potential target for intervention.