Symptoms and Complications
Radical changes in mood and behavior, alternating between highs and lows, are typical signs of cyclothymia. Mood "highs" in cyclothymia are similar to hypomania but do not fulfill complete hypomania criteria (i.e., in cyclothymia the duration of the "high" is less than the four-day minimum for hypomania or there is less than the three associated mental or physical symptoms required for a diagnosis of hypomania). Likewise the mood "lows" in cyclothymia are similar to major depression but do not fulfill full major depression criterion (i.e., in cyclothymia the duration of the depression is less than the two-week minimum required for major depression or there is less than the associated minimum of five mental or physical symptoms found in major depression).
The continual - and unpredictable - mood cycling often takes its toll on an individual's life, even though altered mood episodes aren't as extreme as with manic depression. Mood changes make it difficult to sustain enthusiasm for new projects, or for work. Personal relationships tend to suffer from the "warm-cool" ups and downs associated with hypomanic and depressive episodes, and from the abrupt personality changes that a cyclothymic individual will display. Over time, mood cycling can lead to repeated loss of employment and may become destructive to personal relationships.