Effects of Electroconvulsive Therapy

Effects of stimulus intensity and electrode placement on the efficacy and cognitive effects of electroconvulsive therapy
Authors: Sackeim HA, et al.
N Engl J Med -- 1993 Mar 25;328(12):882-3

Abstract:
BACKGROUND. The efficacy of electroconvulsive therapy in major depression is established, but the importance of the electrical dosage and electrode placement in relation to efficacy and side effects is uncertain.

METHODS. In a double- blind study, we randomly assigned 96 depressed patients to receive right unilateral or bilateral electroconvulsive therapy at either a low electrical dose (just above the seizure threshold) or a high dose (2.5 times the threshold). Symptoms of depression and cognitive functioning were assessed before, during, immediately after, and two months after therapy. Patients who responded to treatment were followed for one year to assess the rate of relapse.

RESULTS. The response rate for low-dose unilateral electroconvulsive therapy was 17 percent, as compared with 43 percent for high-dose unilateral therapy (P=0.054), 65 percent for low-dose bilateral therapy (P=0.001), and 63 percent for high-dose bilateral therapy (P=0.001). Regardless of electrode placement, high dosage resulted in more rapid improvement (P therapy (59 percent) relapsed, and there were no differences between treatment groups.

CONCLUSIONS. Increasing the electrical dosage increases the efficacy of right unilateral electroconvulsive therapy, although not to the level of bilateral therapy. High electrical dosage is associated with a more rapid response, and unilateral treatment is associated with less severe cognitive side effects after treatment.

Electroconvulsive therapy in the treatment-resistant patient.
Authors: Devanand DP, Sackeim HA, Prudic J
Psychiatr Clin North Am
1991 Dec

Abstract:
In medication-resistant patients with major depressive disorder, the response rate with bilateral electroconvulsive therapy (ECT) drops to 50% from the expected range of 80% to 90%. Relapse rates following ECT are high in medication- resistant depressed patients and are clustered in the first 4 months following clinical response. Medication resistance during the index episode predicts a high rate of relapse, whereas those patients who have not received an adequate medication trial prior to ECT are less likely to relapse. If a patient who fails an antidepressant trial then responds to a course of ECT, alternative pharmacologic strategies or maintenance ECT should be considered to decrease the likelihood of relapse. Patients who do not respond to a traditional course of bilateral ECT may respond subsequently to longer courses of bilateral ECT at markedly suprathreshold stimulus intensity, or may respond to a different class of antidepressant medication from that which they failed previously.

Patient selection and remission rates with the current practice of electroconvulsive therapy in Germany
Authors: Kornhuber J, Weller M
Convuls Ther 1995 Jun;11(2):104-109 /TD>