Lesbian, gay, and bisexual (LGB) youth experience elevated levels of depressive symptoms compared to heterosexual youth. This study examined how differences in depressive symptoms between heterosexual and LGB youth developed from late childhood to early adulthood. The association between sexual orientation and depressive symptoms was estimated from age 11 to 22 using data from the TRacking Adolescents' Individual Lives Survey, a longitudinal Dutch cohort study. Of the 1738 respondents (54.8 % girls) that provided information on sexual orientation, 151 self-identified as LGB. In line with the Minority Stress Framework, it was tested whether self-reported peer victimization and parental rejection mediated the association between sexual orientation and depressive symptoms. Results indicated that LB girls and bisexuals were at increased risk of depressive symptoms already at age 11. The difference increased over time and was related to pubertal development in girls and bisexual individuals. Furthermore, self-reported peer victimization (for both boys and girls), as well as parental rejection (for girls/bisexuals), mediated the association between sexual orientation and depressive symptoms. The authors conclude that already in late childhood, associations between sexual orientation and depressive symptoms are found, partly due to minority stress mechanisms.