Medicine Dysthymia, a disorder related to depression, seems to be diagnosed increasingly often. It usually appears in childhood or adolescence, and affects about three percent of the U.S. population. Sufferers are functional but impaired, particularly in social and interpersonal relationships.
Antidepressant medications are often quite helpful in treating dysthymia.
A good reference is Diagnosis and Treatment of Chronic Depression by James H. Kocsis and Daniel N. Klein. When I was in training, we used to think that depressions were either mild and chronic or severe and episodic, but we have since learned that view is probably not accurate. Dysthymia is not so much a new disorder as one that is getting more attention than it used to receive. Although the term is new, dysthymia is based on several older clinical concepts, such as neurotic depression, depressive personality and chronic depression. It is more common among females than among males and can begin at any age, although onsets in childhood and adolescence are particularly common, especially among patients seeking treatment.