dysthymic disorder /disthim″ik/ [Gk, dys + thymos, mind] , a disorder of mood in which the essential feature is a chronic disturbance of mood of at least 2 years’ duration. It involves either depressed mood or loss of interest or pleasure in all or almost all usual activities and pastimes, and associated symptoms, but not of sufficient severity and duration to meet the criteria for a major depressive episode.
