ECT in primary and secondary depression.

The response of depressive symptoms to ECT was studied in 58 subjects who met DSM-III criteria for major depression. For data analysis, the sample was divided by diagnosis into categories of primary unipolar depression, bipolar depression, and secondary depression. Only 56% of the secondary depression group had a partial or complete remission of depressive symptoms, but 91% of the primary unipolar group and 100% of the primary bipolar group improved. Subdividing the secondary depression group by primary diagnosis revealed a differential response, with alcoholism and schizophrenia having the most favorable outcomes.