Bifrontal, bitemporal and right unilateral electrode

most effective treatment for severe major depression. However, there continues to be controversy in the field about optimal methods for administering the treatment. In particular, electrode placement, that is, the anatomic location of the stimulus electrodes on the individual’s scalp, has been the subject of debate for more than 60 years. This debate centres around the balance of the antidepressant efficacy of the treatment against the cognitive effects it produces. Numerous studies and a metaanalysis have concluded that right unilateral ECT is moderately less effective than bitemporal ECT and that it causes fewer cognitive effects. Recently, however, study data suggest that right unilateral electrode placement must be delivered at multiples of seizure threshold to be maximally effective. Thus, much of the literature prior to 2000 contains results that are biased against efficacy in right unilateral placement. A novel placement, bifrontal, has recently gained popularity in clinical practice because it is reported to be equally efficacious to bitemporal placement, but with fewer cognitive effects. The significance of the cognitive effects of ECT as a basis for electrode selection remains highly controversial. Some experts contend that these effects are of little importance compared with the often dramatic lifesaving effects of the treatment. Yet, cognitive effects are the main impediment to the broader application of ECT. To our knowledge, no prior study has directly compared bitemporal, bifrontal and right unilateral ECT. We carried out a multisite, randomised, clinical trial using modern state-of-the-art ECT techniques and comprehensive masked assessments to address the above issues. Method