Definition of Cyclothymic disorder:

Cyclothymic disorder is a mild form of bipolar disorder characterized by alternating episodes of mood swings from mild or moderate depression to hypomania, in which the person experiences elevated mood, euphoria, and excitement, but does not become disconnected from reality.

Causes, incidence, and risk factors:

The cause of cyclothymic disorder is unknown. Although the changes in mood are irregular and abrupt, the severity of the mood swings is far less extreme than that seen with bipolar disorder (manic depressive illness). Unlike in bipolar disorder, periods of hypomania in cyclothymic disorder do not progress into actual mania. In actual mania, a person may lose control over his or her behavior and go on spending binges, engage in highly risky sexual or drug-taking behavior, and become detached from reality.

Hypomanic periods can be energizing and a source of productivity, but may cause some people to become impulsive and unconcerned about others' feelings, which can damage relationships. Because hypomania feels good, some people with cyclothymia do not want to treat it.