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