Childhood psychopathology retrospectively assessed among adults with early onset major depression.

Prevalence and impact of comorbidity in early onset major depressive disorder were studied in 116 depressed adult outpatients whose onset of first major depressive episode occurred by age 18. Eighty-eight percent of these patients had at least one additional comorbid Axis I lifetime diagnosis including: social phobia (28%), simple phobia (16%), alcohol (17%) and cannabis (13%) abuse/dependence, and bulimia nervosa (8%). Comorbid anxiety disorders preceded the onset of major depression in two-thirds of individuals while comorbid substance abuse/dependence followed the onset of major depression in two-thirds and predicted more frequent occurrences into adulthood. In contrast to frequency of episodes, severity and duration of an index episode of major depression were not influenced by comorbidity.