The Bipolar Spectrum

Recent suggestions to extend the boundaries of bipolar disorder to a broader spectrum lead to a concept of bipolarity different from that of classical psychiatry. It has been proposed that many patients with unipolar depression are actually bipolar and that many cases of substance abuse, personality disorders, and childhood behavioral disorders lie within the spectrum. However, since this expanded notion of bipolarity has been defined entirely on the basis of phenomenology, any expansion needs to meet broader criteria for validity. Bipolar spectrum disorders have a different phenomenology, family history, and course than classical bipolar disorders and do not respond in the same way to drugs. Until further research clarifies the boundaries of bipolarity, we should be conservative about extending its scope.