SUMMARY Aim – To review the literature on the efficacy of electroconvulsive therapy [ECT], with a particular focus on depression, its primary target group. Methods – PsycINFO, Medline , previous reviews and meta-analyses were searched in an attempt to identify all studies comparing ECT with simulated-ECT [SECT]. Results – These placebo controlled studies show minimal support for effectiveness with either depression or ‘schizophrenia’ during the course of treatment (i.e. only for some patients, on some measures, sometimes perceived only by psychiatrists but not by other raters), and no evidence, for either diagnostic group, of any benefits beyond the treatment period. There are no placebo-controlled studies evaluating the hypothesis that ECT prevents suicide, and no robust evidence from other kinds of studies to support the hypothesis. Conclusions – Given the strong evidence (summarised here) of persistent and, for some, permanent brain dysfunction, primarily evidenced in the form of retrograde and anterograde amnesia, and the evidence of a slight but significant increased risk of death, the cost-benefit analysis for ECT is so poor that its use cannot be scientifically justified. Declaration of Interest : Neither author has any financial conflicts of interest in relation to this paper.