Definition
In persons with this personality disorder, high-spirited buoyancy alternates with gloom and pessimism; each mood lasts weeks or longer. Characteristically, the rhythmic mood changes are regular and occur without justifiable external cause. This personality disorder is a spectrum variant of manic-depressive illness (bipolar disorder), but most cyclothymic persons do not develop bipolar disorder. Cyclothymic personality is considered a temperament, present in many gifted and creative people.