Medication resistance and clinical response to electroconvulsive therapy.

We examined the extent to which medication resistance during an episode of major depression was related to short-term clinical response to bilateral electroconvulsive therapy (ECT). Strength of pharmacological treatment trials was rated in 53 patients who met Research Diagnostic Criteria for major depressive disorder and were subsequently treated with ECT. Patients who had failed to respond to adequate pre-ECT pharmacotherapy were substantially less likely to respond to ECT than patients who had not received adequate pharmacological trials before ECT. Therefore, medication resistance had predictive value with respect to the therapeutic effects of ECT. The clinical and theoretical implications of this finding are discussed.