Persistent Depressive Disorder

Persistent depressive disorder, also known as dysthymia, is a psychiatric condition whose symptoms resemble those of major depressive disorder but that persist for at least two years in adults, or one year in children, rather than occurring in a single defined episode. The term dysthymia was introduced in the late 1970s as a replacement for the earlier concept of a depressive personality, before the condition's current diagnostic name and criteria took shape. Because its symptoms are often less acutely severe than a major depressive episode even as they persist for years, the disorder can go unrecognized for long periods.