It is hard to ensure that neither psychiatrists nor patients know who did and did not receive ECT, because of the confusion and headaches that frequently immediately follow ECT. In one study the patients in the SECT group, many of whom had had real ECT in the past, “believed that they were receiving some new variation on ECT” (Brill et al., 1959). The UK ECT Review noted that of 73 studies comparing ECT to drug treatment, no treatment or SECT “only two described the method of allocation concealment”. So although comparison with SECT is the best research design it doesn’t eliminate the possibility of placebo effects. Therefore even the very minimal positive benefits reported below may not have been caused by ECT.