Background: Early onset of mood symptoms in bipolar disorder has been associated with poor outcome in many studies; however, the factors that might contribute to poor outcome have not been adequately investigated.
Methods: The first consecutive 1000 adult bipolar patients enrolled in the National Institute of Mental Health's Systematic Treatment Enhancement Program for Bipolar Disorder were assessed at study entry to determine details of their age of onset of mood symptoms. Clinical course, comorbidity, and functional status and quality of life were compared for groups with very early (age < 13 years), early (age 13-18 years), and adult (age > 18 years) onset of mood symptoms.
Results: Of 983 subjects in whom age of onset could be determined, 272 (27.7%) experienced very early onset, and 370 (37.6%) experienced early onset. Earlier onset was associated with greater rates of comorbid anxiety disorders and substance abuse, more recurrences, shorter periods of euthymia, greater likelihood of suicide attempts and violence, and greater likelihood of being in a mood episode at study entry.
Conclusions: Very early or early onset of bipolar disorder might herald a more severe disease course in terms of chronicity and comorbidity. Whether early intervention might modify this risk merits further investigation.