The essential feature of cyclothymic disorder is a chronic, fluctuating mood disturbance involving numerous periods of hypomaniac symptoms and periods of depressive symptoms that are distinct from each other (Criterion A). The hypomaniac symptoms are of insufficient number, severity, pervasiveness, or duration to meet full criteria for a hypomaniac episode, and the depressive symptoms are of insufficient number, severity, pervasiveness, or duration to meet full criteria for a major depressive episode. During the initial 2-year period (1 year for children or adolescents), the symptoms must be persistent (presents more days than not), and any symptom-free intervals last no longer than 2 months (Criterion B).*

 

*Diagnostic and Statistical Manual of Mental Disorders: DSM-5. 5th ed. Washington, D.C.: American Psychiatric Association, 2013. 140. Print