Stabilization of mood from below versus above baseline in bipolar disorder: a new nomenclature.

Management of bipolar disorder has traditionally emphasized the acute treatment of mania. Although acute treatment of mania is a critical aspect of care, this emphasis has tended to overshadow other important phases of bipolar disorder, such as depression, hypomania, and subsyndromal symptoms. We offer a reconceptualization of bipolar disorder that highlights unmet needs and the importance of differential spectra of efficacy. In this reconceptualization, bipolar disorder can be viewed as an aberration of mood, behavior, and cognition from baseline (euthymia). "Below baseline" is characterized by depression and subsyndromal depression. "Above baseline" is characterized by mania, mixed states, hypomania, and subsyndromal mood elevation. In contrast to the treatment options for mania, the options for depression are limited. This new nomenclature emphasizes the need to develop mood stabilizers that possess the ability to stabilize mood "from below baseline," either alone or in combination with other agents. In this article, the treatment options for bipolar disorder, with a focus on depression and rapid cycling, are discussed according to this new conceptualization of management from below and above baseline.