Minor versus major depression: a comparative clinical study

To examine whether minor depression differs from major depression in clinically relevant ways.

Structured interviews, Symptom Checklist-90-Revised (SCL-90-R) scores, and physicians' treatment recommendations were obtained systematically from 1,458 admissions to an outpatient teaching clinic during a 5-year period from 1981 to 1986. Of these, 1,002 (69%) satisfied inclusive DSM-III lifetime criteria for a major depressive episode. Of the 456 outpatients who did not formally satisfy criteria for a major depressive episode, 79 (17%) acknowledged significant depressive symptoms that caused major interference in their lives. These 79 outpatients were classified as suffering from minor depression.

No gender or other sociodemographic differences were found between the 2 outpatient groups except that the minor depression group had achieved a higher level of education. No differences were found for a family history of psychiatric illness among first-degree relatives, including a family history of depression. Ratings of childhood unhappiness/problems did not distinguish the 2 groups. The major depression group endorsed more lifetime depressive symptoms and met criteria for more co-occurring disorders, principally mania and the anxiety disorders. The group with major depression reported poorer psychosocial functioning when first seen and more past psychiatric treatment. The Symptom Checklist-90-Revised (SCL-90-R) profile was significantly elevated in both groups. The type of initial treatment recommended did not distinguish the major from minor depression groups.

Minor depression seems to represent the same illness as major depression but in a less severe form that, nevertheless, requires the attention of professional health care providers in both primary and specialized care settings.