Bifrontal, bitemporal and right unilateral electrode placement in ECT: randomised trial

Abstract

Background: Electroconvulsive therapy (ECT) is an effective treatment for major depression. Optimising efficacy and minimising cognitive impairment are goals of ongoing technical refinements.

Aims: To compare the efficacy and cognitive effects of a novel electrode placement, bifrontal, with two standard electrode placements, bitemporal and right unilateral in ECT.

Method: This multicentre randomised, double-blind, controlled trial (NCT00069407) was carried out from 2001 to 2006. A total of 230 individuals with major depression, bipolar and unipolar, were randomly assigned to one of three electrode placements during a course of ECT: bifrontal at one and a half times seizure threshold, bitemporal at one and a half times seizure threshold and right unilateral at six times seizure threshold.

Results: All three electrode placements resulted in both clinically and statistically significant antidepressant outcomes. Remission rates were 55% (95% CI 43-66%) with right unilateral, 61% with bifrontal (95% CI 50-71%) and 64% (95% CI 53-75%) with bitemporal. Bitemporal resulted in a more rapid decline in symptom ratings over the early course of treatment. Cognitive data revealed few differences between the electrode placements on a variety of neuropsychological instruments.

Conclusions: Each electrode placement is a very effective antidepressant treatment when given with appropriate electrical dosing. Bitemporal leads to more rapid symptom reduction and should be considered the preferred placement for urgent clinical situations. The cognitive profile of bifrontal is not substantially different from that of bitemporal.

Figures

Fig. 1

Participant flow. ECT, electroconvulsive therapy. a. Modified ITT sample (a priori defined). b. Participant perception or clinician determined.

Fig. 2

Observed Hamilton Rating Scale for Depression–24 (HRSD–24) total score means.

Fig. 3

Fitted Hamilton Rating Scale for Depression–24 (HRSD–24) total score means from longitudinal mixed models analysis with linear and quadratic terms for time. †Bitemporal v. right unilateral: 0.01≤P≤0.058; ‡bitemporal v. right unilateral: P = 0.085; §bitemporal v. bifrontal: P<0.05; #bitemporal v. bifrontal: P = 0.081.

Fig. 4

95% CI estimates of remission proportions for bitemporal (BT), bifrontal (BF) and right unilateral (RUL) electrode placements.