In the context of a prospective, longitudinal, and controlled nosologic study, the characteristics and diagnostic validity of major depressive disorder, dysthymic disorder, and adjustment disorder with depressed mood were examined in a school-aged cohort. The entities were distinguishable on several dimensions such as age at onset and pattern of recovery. Time to recovery from onset was most favorable for the adjustment disorders (90% remission rate during nine months) and least so for the dysthymias (89% remission rate during six years). Major depression and dysthymia were similar with respect to the prevalence of concurrent nonaffective disorders. For both, early age at onset predicted a more protracted illness. Treatment contacts, none of which were under the control of the investigators, had no clear impact on recovery from the depressions.