This study applies latent growth curve analysis to data from three waves of the National Longitudinal Study of Adolescent Health (n = 10,828) and finds that symptoms of depression and social support interact with one another in a dynamic fashion across the transition from adolescence (mean age at Wave 1 = 15.28 years) to young adulthood (mean age at Wave 3 = 21.65 years). Parental support during adolescence is inversely associated with initial symptoms of depression for girls and boys, although adolescent girls with low levels of parental support begin the study period with significantly higher levels of depressive symptomatology than their male counterparts. In addition, adolescents who begin the study period with higher levels of depressive symptomatology report less parental support during young adulthood. Finally, regardless of their initial level of depressive symptoms, girls and boys who experience increased symptoms of depression over time also report lower levels of parental support at the end of the study period.