Background:
Cross-sectional studies indicate that depression is strongly associated with sexually transmitted infection (STI) among adolescents in the United States (US). Investigation of the longitudinal relationship between depression through adolescence and biologically-confirmed STI in young adulthood is needed.

Objective:
To measure associations between major depressive disorder (MDD) from adolescence through young adulthood and indicators of STI risk - biologically-confirmed infection (STI) and high-risk sexual behaviors - among young adults in the United States.

Method:
We used Wave I (1995: adolescence) and Wave III (2001-2002: young adulthood) of the National Longitudinal Study of Adolescent Health (N=13,123) to estimate associations between a four-level indicator of MDD timing and duration (chronic MDD [in adolescence and adulthood]; recent MDD [in adulthood only]; prior MDD [in adolescence only]; no prior MDD) and STI risk indicators separately for white and minority (black/Latino) men and women.

Result:
The prevalence of ever having MDD in adolescence or adulthood was more common among minorities (women: 36%, men: 24%) than whites (women: 27%, men: 16%). When adjusting for age, socio-economic status, and STI during adolescence, having an STI in adulthood was associated with chronic MDD among minority men (prevalence odds ratio (POR): 2.57, 95% confidence interval (CI): 1.30-5.08) and prior MDD among minority women (POR: 1.56, 95% CI: 0.97-2.51) (referent: no prior MDD). Low condom use likely constituted a modifiable factor underlying high levels of STI among minorities with MDD. Among whites, MDD was not associated with STI but was associated both with multiple sexual partnerships and never using condoms in the past year.

Conclusion:
MDD was associated with STI and high-risk behaviors among minorities and high-risk behaviors among whites.

Implications:
Integration of youth mental health and STI treatment and prevention programs is warranted, particularly in minority communities, where MDD is more prevalent and more strongly associated with STI.