Sham electroconvulsive therapy studies in depressive illness: a review of the literature and consideration of the placebo phenomenon in electroconvulsive therapy practice.

The gold standard for the establishment of therapeutic efficacy is the randomized placebo-controlled trial. In the case of electroconvulsive therapy (ECT), there is an older literature of a dozen so-called "sham ECT" trials. When cited, these trials are typically referred to as unequivocally demonstrating the superiority of ECT over sham ECT. However, there is an intriguingly high sham ECT response rate in some of the studies, and there is also some information regarding ECT response of depressive subtypes that informs the modern ECT practitioner. In this report, the sham ECT literature is reviewed in detail, and the author discusses possible mechanisms by which sham-treated patients improved.