Objective: We examined age of onset of bipolar disorder as a potential course-of-illness modifier with the hypothesis that early onset will engender more severe illness.
Study design: A total of 480 carefully diagnosed adult outpatients with bipolar disorder (mean age, 42.5 +/- 11.6 years) were retrospectively rated for age of illness onset, time to first pharmacotherapy, and course of illness. Clinicians prospectively rated daily mood fluctuations over 1 year.
Results: Of the 480 patients, 14% experienced onset in childhood (12 years or younger); 36% in adolescence (13 to 18 years); 32% in early adulthood (19 to 29 years); and 19% in late adulthood (after 30 years). Childhood-onset bipolar illness was associated with long delays to first treatment, averaging more than 16 years. The patients with childhood or adolescent onset reported more episodes, more comorbidities, and rapid cycling retrospectively; prospectively, they demonstrated more severe mania, depression, and fewer days well.
Conclusions: This study demonstrates that childhood onset of bipolar disorder is common and is associated with long delays to first treatment. Physicians and clinicians should be alert to a possible bipolar diagnosis in children in hopes of shortening the time to initiating treatment and perhaps ameliorating the otherwise adverse course of illness.