Background: The age of onset of major depression may produce divergent profiles of recovery after treatment.
Methods: Symptom level and course trajectories of with early- and adult-onset of major depression were followed prospectively over 2 years in 62 adult outpatients who recovered from DSM-III-R unipolar major depression after cognitive behavior therapy. We compared individuals with depression onset before age 20 (n = 31) with those with onset after age 20 (n = 31), controlling for current age, education, and history of depression, and accounting for their return to mental health treatment. Participants completed psychiatric and psychosocial assessments before and after treatment, and every 6 months for 2 years post-treatment. We analyzed severity and changes of weekly depressive symptoms to construct profiles of recovery for the early- and adult-onset groups.
Results: Our data indicated: (a) on average, the early-onset group experienced consistently more depressive symptoms than the adult-onset group; (b) the pattern of symptoms remained level for both groups during the 2-year follow-up; (c) both groups maintained parallel and stable course profiles over the 2-year follow-up; and, (d) early age of onset was associated with higher rate of depressive relapse.
Limitations: Accuracy of the ratings of depressive symptoms may have been limited by the retrospective nature of the psychiatric status ratings.
Conclusions: Results suggest that among our recovered participants, early age of onset is associated with shorter time to relapse, more residual symptoms over the follow-up, and a stable and linear course of residual symptoms during the 2-year follow-up.