In contrast to debates 2 decades ago, it is now clear that major depressive disorder (MDD) often has an onset in adolescence,
1-6 across diverse countries,
7,8 and is associated with substantial psychosocial impairment
6,9-15 and risk of suicide.
12,16 Despite the high prevalence and morbidity, it is not clear if adolescent-onset MDD predicts mood disorder and impairment in adult life. This information is clearly important in guiding early treatment.