The authors examined whether adolescent major depressive disorder (MDD) was associated with difficulties in young adult functioning and whether differences would remain significant after accounting for nonmood disorder, MDD recurrence, functioning in adolescence, or current mood state. A total of 941 participants were assessed twice during adolescence and at age 24. In unadjusted analyses, adolescent MDD was associated with most young adult functioning measures. Associations were not due to interactions with adolescent comorbidity, but differences in global functioning and mental health treatment appeared as a result of MDD recurrence. Accounting for levels of functioning in adolescence or for current depression at age 24 eliminated the remaining associations. The implications of these findings for efforts to prevent MDD in adolescence are discussed.