A review of treatment studies of minor depression: 1980-1991.

This article provides a brief overview of the changing nature of the concept of minor depression. It then discusses treatment studies conducted from 1980 to 1991 of patients diagnosed as neurotic depression, depressive neurosis or dysthymia, characterologic depression, "double depression" and minor depression or dysthymia, if there has been a full remission of a major depressive episode lasting at least six months prior to the development of dysthymia. Long-term treatment of chronic depression is also reviewed. Cognitive-behavioral intervention and marital therapy have been reported beneficial for patients diagnosed as having neurotic depression, characterological depression, or dysthymia. All studies of antidepressant drug treatment showed drugs to be efficacious and superior to placebo, with few differences found between drugs. In addition, they all showed the importance of analyzing the interactions between treatment and severity or diagnosis. Patients diagnosed as "double depression" also appear responsive to both psychosocial intervention and drug treatment; in general, however, these patients tend to have a poor long-term outcome and continued treatment is indicated. The most obvious finding to emerge from this review is that the diagnosis of minor depression is ambiguous, in large part because of the lack of defining criteria related to severity and course. The review also revealed that in addition to poorly defined subgroups, many studies lacked controls, had small sample sizes, inadequate and/or inconsistent measures of outcome, and limited follow-up. For these reasons, their findings cannot be considered conclusive. Finally, the literature revealed a dearth of controlled studies of psychosocial treatment for well defined subgroups of neurotic depression.