Cyclothymic disorder, or cyclothymia, is a form of bipolar disorder characterized by distinct episodes of hypomanic symptoms (elevated mood and euphoria) and depressive symptoms over a period of at least two years. The mood fluctuations are not sufficient in number, severity, or duration to meet the full criteria for a hypomanic or depressive episode, but they are present more than 50 percent of the time and no more than two months elapse without symptoms.
Hypomania involves periods of elevated mood, euphoria, and excitement but does not disconnect a person from reality. A person with cyclothymia experiences symptoms of hypomania but not full-blown manic episodes. Hypomania may feel good to the person who experiences it and may lead to enhanced functioning and productivity. Thus, even when family and friends learn to recognize the mood swings as a possible bipolar disorder, the person may deny that a problem exists. Without proper treatment, however, symptoms can worsen.
Approximately 0.4 percent to one percent of people will experience cyclothymia in their lifetime. The disorder usually begins in adolescence or early adulthood and it is lifelong. There is a 15 percent to 50 percent risk that a person with cyclothymic disorder will go on to develop bipolar I or bipolar II disorder, although many people do recover from cyclothymia and do not experience future symptoms of hypomania or depression. Cyclothymic disorder is equally common in males and females. It may co-occur with substance-use disorder or anxiety disorder.