Response to Kellner and Fink

To the Editor: We find the point made by Drs. Kellner and Fink regarding efficacy related to ECT treatment technique with reference to our study important and clinically relevant.

When planning our study, the status regarding efficacy and side effects of ECT treatment technique was suggestive but not conclusive of bilateral electrode placement compared with high-dose unilateral electrode placement being more effective. Cognitive side effects related to ECT treatment, on the other hand, were understudied regardless of ECT treatment technique, but bilateral compared with unilateral electrode placement seemed to carry a higher risk for long-term cognitive side effects (1, 2). This was the reason for choosing the right unilateral electrode placement in our study.

The large-scale study by the Consortium for Research in Electroconvulsive Therapy (CORE) group (3) has since added further support to the notion that bilateral electrode placement may be more effective than unilateral electrode placement in terms of speed of decreasing depressive symptoms without being associated with more cognitive side effects. In line with this, Drs. Kellner and Fink argue that the higher mean number of ECT treatments in our study compared with that in the CORE study may represent the use of the less effective unilateral electrode placement. Although we cannot rule out such an effect, the difference in efficacy in terms of speed and remission between the two studies may have well been caused by the differences in patient population.

The final comment by Drs. Kellner and Fink that “in real-world clinical settings, the option to use the most potent ECT techniques is an important aspect of optimized, ethical care” gives an impression that this is a straightforward choice but does not take into account the increased risk for retrograde amnesia associated with bilateral electrode placement. We find that Allan Scott (4) balanced the evidence regarding efficacy and side effect when he commented in an editorial that “there is no ideal electrode placement,” but method has to be weighted against the clinical condition and cognitive risk profile.