Previous studies, performed mainly in the second half of the last century, focused primarily on the two extreme clinical manifestations of major mood disorders (i.e., unipolar major depression and “classical” bipolar I disorder), and found marked differences in almost all clinical features and diagnostic validators, virtually supporting the strict categorical distinction between unipolar major depressive disorder and “bipolar” disorder. However, a number of recent studies clearly support the original “unitary” concept of Emil Kraepelin on the continuity between unipolar depression and manic-depressive illness. Nowdays it is well accepted that bipolar I (major/minor depression with a history of mania) and bipolar II (major depression with a history of hypomania but not with mania) disorders represent two prominent clinical phenotypes at the “bipolar edge” of the full unipolar-bipolar spectrum with several similarities and differences. Phenomenologically, bipolar II disorder is more close to bipolar I disorder than to unipolar depression, and, particularly if the subthreshold cases of hypomania are also considered, bipolar II is the most common form of bipolar disorders both in clinical settings and in the general population. While the basic similarity between bipolar I and bipolar II is the two different (“positive” and “negative”) pathological levels of mood and activity, there are several important differences between them, such as: 1, Familiy history of specific mood disorders, 2, Affective temperament, 3, Cross-sectional clinical picture of depression, 4, Long-term course, 5, Psychiatric and medical comorbidity, 6, Gender ratio, 7, Long-term course and 8, Suicidal behavior.
Although there is no fundamental difference in the acute and long-term pharmacotherapy between bipolar I and bipolar II disorders, because of the more complex clinical presentation and more recurrent nature of bipolar II, its pharmacological treatment is also more complex.
Prophylactic lithium therapy seems to exert greater anti-suicidal potential in bipolar II patients.
This post was submitted by Prof Zoltan Rihmer.
