How is dysthymic disorder different from other types of depression?
Most of the time when people talk of “depression,” they mean “major depression.”
Major depression is generally severe, and fairly brief in duration—lasting perhaps weeks or months. In major depression, mood drops markedly, and is usually accompanied by poor sleep, loss of appetite, weight loss, hopelessness, and often with suicidal ideas. In contrast, DD is not as severe on a day-to-day basis, and it lasts for years (even decades) rather than weeks or months.
Many times, people who present for treatment of depression actually have “double depression.” That is, they have a longstanding problem of chronic low-grade depression, but now they are also in a state of major depression.
It is important to try to tell if a person has double depression—since if they are treated and simply return to their usual chronically depressed state, they have not really gotten well!