Cyclothymic disorder is a recurrent, chronic, mild form of bipolar disorder in which mood typically oscillates between hypomania and dysthymia. It is not diagnosed if a person has had either a manic episode or a major depressive episode.

Epidemiology

The lifetime prevalence of cyclothymic disorder is 0.4% to 1%. The rate appears equal in men and women, though women more often seek treatment.

Etiology

Familial and genetic studies reveal an association with other mood disorders.

Clinical Manifestations

History and Mental Status Examination
Cyclothymic disorder is a milder form of bipolar disorder consisting of recurrent mood disturbances between hypomania and dysthymic mood. A single episode of hypomania is sufficient to diagnose cyclothymic disorder; however, most individuals also have dysthymic periods. The diagnosis of cyclothymic disorder is never made when there is a history of mania or major depressive episode or mixed episode. The course of untreated cyclothymic disorder is depicted in Figure 2-2C.

Differential Diagnosis
The principal differential is among other unipolar and bipolar mood disorders, substance-induced mood disorder, and mood disorder due to a general medical condition. Personality disorders (especially borderline) with labile mood may be confused with cyclothymic disorder.

Management
Psychotherapy, mood stabilizers, and antidepressants are used. However, persons with cyclothymia may never seek medical attention for their mood symptoms.