Longitudinal studies of community samples of children and adolescents suggest an average age of onset between 11 and 14 years35 for MDD and depressive disorder (DD). Evidence from prospective epidemiologic studies reveals a large change in the prevalence of major depressive episodes after age ll.36 Prospective data from the Oregon Adolescent Depression Project showed that the rates of new onsets of depression increase from 1 % to 2% at age 13 and from 3% to 7% at age 15.20 The incidence of depression continues to increase throughout early adulthood.37 There do not appear to be gender differences in the average age of onset of MDR in the National Comorbidity Survey.20,38
