Treatment and outcome in secondary depression: a naturalistic study of 1087 patients.

In a naturalistic study, the treatment response and outcome of 1087 patients with nonbipolar primary (N = 763) and secondary (N = 324) depression were compared by a chart review. The patients were divided into four treatment groups, based on the primary mode of therapy received during the index hospitalization: ECT, adequate antidepressant, inadequate antidepressant, and neither treatment. Primary depressives were more likely to have received ECT, and secondary depressives were more likely to have received inadequate antidepressant or neither treatment. A total of 436 (57.1%) primary depressives received adequate therapy, but only 113 (34.9%) secondary depressives did (p less than .001). Overall, primary depressives responded better to treatment (both ECT and antidepressants) than did secondary depressives. A total of 470 (61.6%) primary depressives but only 140 (43.2%) secondary depressives were recovered at discharge (p less than .001). The conclusion is that secondary depressives are more likely to receive inadequate treatment and are less likely to respond to adequate treatment than are primary depressives.