Using prospective, longitudinal data from 467 youth over a 13-year period (late adolescence and young adulthood), the present study investigates three research questions: (1) to what extent do elevations in depressed mood continue (homotypic continuity) from adolescence to young adulthood, (2) to what extent do young adults' socioeconomic attainments and failures sustain the depressed mood from adolescence to young adulthood, and (3) to what extent do young adults' socioeconomic attainments or failures mediate the continuity and discontinuity of depressive symptoms across this period? The results from our structural equation modeling ("SEM") analyses suggest that continuity of depressive symptoms from late adolescence to young adulthood is mediated in part by economic and work achievements or failures of young adults after controlling for adolescent conduct disorder/antisocial behavior, parents' psychopathology and family adversity. Additionally, the results indicate that the continuity of depressed mood across the early life course is conditioned (stabilized or disrupted) by young adult socioeconomic achievements or failures. (Contains 2 tables and 1 figure.)