SECULAR TRENDS IN AGE AT ONSET OF MAJOR DEPRESSIVE DISORDER IN A CLINICAL-SAMPLE OF CHILDREN

Using a psychiatrically referred, depressed, school-age sample, we sou ght to cross-validate the clinically pertinent epidemiologic finding t hat the distribution of age at onset of first episode of major depress ive disorder (MDD) is subject to birth-cohort and period effects. Demo graphic and historical variables also were considered in attempting to explain the variability in age-at-onset. The results indicated a birt h-cohort effect, but no discernable period effect on age at onset of M DD; successive birth cohorts were younger when they first developed MD D even after stringent analyses were conducted that corrected for stru ctural sampling biases in the sample. In view of the relatively small size and clinical nature of the sample and the restricted birth-year s pan that characterizes children, the results are presented to stimulat e further discussion of this topical area.