Cyclothymia is a serious mood and mental disorder that causes both hypomanic and depressive episodes. It is defined medically within the bipolar spectrum and consists of recurrent disturbances between sudden hypomania and dysthymic episodes. The diagnosis of cyclothymic disorder is not made when there is a history of mania or major depressive episode or mixed episode. The lifetime pre-eminence of cyclothymic disorder is 0.4-1%. The rate appears equal in men and women, though women more often seek treatment. Unlike some other forms of bipolar disorder (to be specific, bipolar I disorder), people with cyclothymia are almost always fully functioning, sometimes even hyper-productive.
Cyclothymia is similar to bipolar II disorder in that it presents itself in signature hypomanic episodes. Because hypomania is often associated with exceptionally creative, outgoing, and high-functioning behavior, both conditions are often undiagnosed. As with most of the disorders in the bipolar spectrum, it is the depressive phase that leads most sufferers to get help.
This disorder is common in the relatives of patients with bipolar disorder, and some individuals with cyclothymia eventually develop bipolar disorder themselves. It may persist throughout adult life, cease temporarily or permanently, or develop into more severe mood swings, meeting the criteria for bipolar disorder or recurrent depressive disorder in rare cases.