A prospective, randomized, double-blind comparison of bilateral and right unilateral electroconvulsive therapy at different stimulus intensities.
BACKGROUND
Controversy persists about the use of right unilateral (RUL) and bilateral (BL) electroconvulsive therapy (ECT). While RUL ECT results in less severe short-term and long-term cognitive effects, there is concern that it is less efficacious than BL ECT.


METHODS
In a double-blind study, 80 depressed patients were randomized to RULECT, with electrical dosages 50%, 150%, or 500% above the seizure threshold, or BL ECT, with an electrical dosage 150% above the threshold. Depression severity and cognitive functioning were assessed before, during, immediately after, and 2 months after ECT. Compared with baseline, responders had at least a 60% reduction in symptom scores 1 week after ECT, and were monitored for relapse for 1 year.


RESULTS
High-dosage RUL and BL ECT were equivalent in response rate (65%) and approximately twice as effective as low-dosage (35%) or moderate-dosage (30%) unilateral ECT. During the week after the randomized phase, BL ECT resulted in greater impairment than any dosage of unilateral ECT in several measures of anterograde and retrograde memory. Two months after ECT, retrograde amnestic deficits were greatest among patients treated with BL ECT. Thirty-three (53%) of the 62 patients who responded to ECT relapsed, without treatment group differences. The relapse rate was greater in patients who had not responded to adequate pharmacotherapy prior to ECT and who had more severe depressive symptoms after ECT.


CONCLUSIONS
Right unilateral ECT at high dosage is as effective as a robust form of BL ECT, but produces less severe and persistent cognitive effects.
Sackeim
H A
HA
Department of Biological Psychiatry, New York State Psychiatric Institute, NY 10032, USA. has1@columbia.edu
Prudic
J
J
Devanand
D P
DP
Nobler
M S
MS
Lisanby
S H
SH
Peyser
S
S
Fitzsimons
L
L
Moody
B J
BJ
Clark
J
J
D000647:Amnesia / Q000175:diagnosis / Q000209:etiology; D000648:Amnesia, Retrograde / Q000175:diagnosis / Q000209:etiology; D000928:Antidepressive Agents / Q000627:therapeutic use; D018592:Cross-Over Studies; D003866:Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy / Q000628:therapy*; D004311:Double-Blind Method; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D004565:Electroconvulsive Therapy / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D009483:Neuropsychological Tests; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012008:Recurrence; D012720:Severity of Illness Index; D016896:Treatment Outcome
D000928:Antidepressive Agents