Dysthymia ( dihs-THIY-mee-uh), also known as persistent depressive disorder (PDD), is a mental and behavioral disorder, specifically a disorder primarily of mood, consisting of similar cognitive and physical problems as major depressive disorder, but with longer-lasting symptoms. The concept was used by Robert Spitzer as a replacement for the term "depressive personality" in the late 1970s. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) indicates that persistent depressive disorder— the new name for what was called dysthymic disorder in DSM-IV—is a serious state of chronic depression, which persists for at least two years (one year for children and adolescents)...