Dysthymia, also known as persistent depressive disorder (PDD) or dysthymic disorder, is a mood disorder characterized by the same mental and physical symptoms as depression but they last longer. Dysthymia is chronic but less severe than major depressive disorder.
Dysthymia can occur in childhood and adulthood, and the average age onset of this condition is 31. In the US, the lifetime rate of dysthymia is 1.5 to 15%, depending on the study. Dysthymia is slightly more common in women than in men.
Dysthymia often coexists with other conditions such as anxiety disorder (up to half), personality disorders (up to 40%), and alcohol and substance abuse (up to half).