Bipolar Disorder Consortium

Objective: Bipolar affective disorder is clinically heterogeneous, and clinical fea-tures that run in families may help define more homogeneous phenotypes. The au-thors sought to establish whether polarity at illness onset, which is related to sever-ity and course, is a familial feature of bi-polar affective disorder. Method: The authors studied 971 sub-jects from 507 families ascertained through sibling pairs with bipolar I or schizoaffective bipolar disorder. Self-re-ported ages at onset of mania and major depression were used to code polarity at onset as manic, major depressive, or bot