Just as there is a milder cousin of depression called dysthymia, so too there is a milder occurrence of bipolar disorder called cyclothymia.
Like bipolar disorder, cyclothymia has high and low phases, though the highs are not as high and the lows not as low as full-blown bipolar.
The upbeat phase features symptoms such as elevated mood, increased self-esteem, decreased need for sleep, racing thoughts, an increase in goal-directed activity, and excessive involvement in pleasurable activities. These symptoms may last 4 or 5 days and are followed by an alternate phase of mild depression symptoms such as sadness, pessimism, fatigue, feeling guilty, trouble concentrating and changes in sleep or appetite.
Though these symptoms may be manageable, if they persist for two years or more, intervention should be taken because 50% of those with cyclothymia end up with bipolar disorder, and major depression is also a higher risk.
The American Psychiatric Association estimates that 2.2 million U.S. adults have cyclothymia, about half as many as those with bipolar disorder. But as bipolar disorders have gained visibility in the clinical community and popular culture, cyclothymia is being identified and treated more often.