US researchers describe clinical course of bipolar disorder in youths

US researchers studying the course of bipolar disorder (BP) in youths report "a dimensional continuum of BP symptom severity, from sub-syndromal to mood syndromes meeting full DSM-IV criteria".The researchers describe the early clinical course and some relevant predictors of outcome in youths with bipolar I disorder (BP-I, n=151), BP-II (n=20) and BP not otherwise specified (BP-NOS, n=92) who were recruited as part of a larger multi-site study - the Course and Outcome of Bipolar Illness in Youth (COBY).Children and parents were interviewed directly at baseline for the presence of current and lifetime non-mood psychiatric disorders, mania and depression in the child.Longitudinal changes in participants' psychiatric symptoms, functioning and treatment exposure were assessed every 35.5 weeks for a mean of 94.8 weeks using the Longitudinal Interval Follow-Up Evaluation (LIFE).Overall, 68% of participants recovered from their index episode a median of 78 weeks after onset. Fifty-six per cent of participants suffered at least one recurrence a median of 61 weeks after recovery from the index episode.On average, participants spent 39.7% of the follow-up time without clinically significant mood symptoms, 22.4% of the time in a DSM-IV syndromal episode, 37.9% of the time with sub-syndromal symptoms and 3.1% of the time with clinically significant psychotic symptoms.Eighty-six per cent of the study group experienced more than three changes in symptom status per year, with more changes occurring in BP-NOS participants than in those with BP-I or BP-II.Just under a fifth of participants changed polarity once per year or less while 30% changed more than 20 times per year. During follow-up, 21% of BP-II participants changed to BP-I. Twenty per cent of those with BP-NOS changed to BP-I while a further 10% changed to BP-II.Early BP onset, lower socioeconomic status, BP-NOS, longer duration of BP and lifetime psychosis were associated with worse outcomes as well as a greater number of changes in symptom status and polarity per year.A secondary analysis revealed that youths with BP-I spent significantly more time symptomatic and had more mixed/cycling episodes, mood symptom changes and polarity switches than adults with BP-I.The researchers conclude that early recognition and effective treatment of BP spectrum disorders in youths is vital, to ameliorate ongoing syndromal and sub-syndromal symptoms and to limit the serious psychosocial morbidity that usually accompanies this illness.Reference...