Stressful transitions in adolescence increase depressive symptoms, especially among girls. However, little is known about this risk as adolescents mature into young adulthood, especially about how parental support affects depression trajectories during this period. Using the National Longitudinal Study of Adolescent Health, this analysis investigates the role of gender in structuring the associations among stressful life events, parental support, and depression. Females reported more depressive symptoms at the outset of the study, a rank order that persisted along declining depression trajectories into young adulthood. In addition, stress accounts for the decline in trajectories for females but not males. Support from both parents has a salubrious effect on mental health, regardless of gender, but this effect dissipates as adolescents age into adulthood.