A diagnosis of exclusion in which for at least 2 years there have been many periods of hypomanic symptoms and numerous periods with depressive symptoms that do not meet the criteria for major depressive episode. During the 2-year period, the person must show the symptoms mentioned for more than 2 months at a time. In addition, no major depressive episode, manic episode, or mixed episode can be present during the first 2 years of the disturbance. The symptoms cannot be accounted for by a psychosis and are not due to drugs or a general medical condition. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.