Definitional issues in bipolar disorder across the life cycle.

This article reviews the current diagnostic criteria for bipolar mood episodes and disorders, emphasizing gaps and limitations in the current definitions. The review also discusses terms that have been perceived as inconsistent between child versus adult presentations of bipolar disorders, such as “rapid cycling.” The review links the DSM diagnoses to broader discussions of a bipolar spectrum, and to alternate definitions of “narrow,”“intermediate,” and “broad” phenotypes. Strengths and limitations of dimensional models of bipolar disorder are discussed. The bulk of the evidence suggests that research and clinical practice will advance more rapidly by using a consistent set of definitions for bipolar disorder across the life cycle.