Bipolar Disorders: Mixed States, Rapid-Cycling, and Atypical Forms

101 Bipolar I and bipolar II: a dichotomy?ConclusionFrom a clinical and therapeutic point of view, bipolarity looks clearly dimensional.The strongest support for the theory that bipolar II disorder ‘‘breeds true’’ comesfrom genetic studies. Pathophysiological and neuroimaging studies are still inconclusive.The dimensionality of the bipolar spectrum runs against the existence of atrue dichotomy between bipolar I and bipolar II. In fact, as far as the molecular level,it seems to be uncategoric. Dichotomies are useful for education, communication,and simplification; unfortunately, simplicity is useful but untrue, whereas complexityis true, but useless. In clinical practice, we may use current classifications, such asDSM-IV, as categoric backgrounds that may help to establish the treatment andprognosis. However, the presence of mixed symptoms in many bipolar II patients,their not-so-rare switch into mania, and the need for vigorous treatment to deal withthe high frequency of relapse may make the apparent dichotomy less likely to shedlight on the nature of bipolarity and the needs of our patients.AcknowledgmentsThis work was supported by the Stanley Research Foundation (Bethesda,MD, USA).REFERENCESAkiskal, H. S. (1983). The bipolar spectrum: new concepts in classification and diagnosis.In Psychiatry Update: The American Psychiatric Association Annual Review, ed. L. Grinspoon,pp. 271–92. Washington, DC: American Psychiatric Press.Akiskal, H. S. (2002a). Classification, diagnosis and boundaries of bipolar disorders: a review. InBipolar Disorder, ed. M. Maj, H. S. Akiskal, J. J. López-Ibor, and N. Sartorius, pp. 1–52. NewYork: John Wiley.Akiskal, H. S. (2002b). Towards a new classification of bipolar disorders. In Bipolar Disorders.Clinical and Therapeutic Progress. ed. E. Vieta, pp. 185–215. Madrid: Panamericana.Akiskal, H. S., and Mallya, G. (1987). Criteria for the ‘‘soft’’ bipolar spectrum: treatmentimplications. Psychopharmacol. Bull., 23, 68–73.Akiskal, H. S., Walker, P., Puzantian, V. R., et al. (1983). Bipolar outcome in the course ofdepressive illness. J. Affect. Disord., 5, 115–28.Akiskal, H. S., Maser, J. D., Zeller, P. J., et al. (1995). Switching from ‘‘unipolar’’ to bipolar II.An 11-year prospective study of clinical and temperamental predictors in 559 patients. Arch.Gen. Psychiatry, 52, 114–23.Akiskal, H. S., Bourgeois, M. L., Angst, J., et al. (2000). Re-evaluating the prevalence of anddiagnostic composition within the broad clinical spectrum of bipolar disorders. J. Affect.Disord., 59, 5–30.