What is dysthymia?
Dysthymia, sometimes referred to as mild, chronic depression, is less severe and involves fewer symptoms than a major depressive episode. In modern diagnostic classifications, the term "dysthymia" has been changed to "persistent depressive disorder." With persistent depressive disorder, the depression symptoms linger for a long period of time -- at least two years or longer in adults, or one year or longer in adolescents. People with this condition can also experience periods of major depression superimposed on low-grade depressions. This is sometimes called "double depression."