This absence of evidence that ECT has any benefits beyond the treatment period is often countered by ECT advocates with the argument that this does not matter because the person can be treated subsequently with antidepressants. However, a well-designed study of subsequent pharmacotherapy followed up, for six months, the 159 of 290 (55%) patients with uni-polar depression who had shown improvement during ECT (Sackeim et Other ECT researchers have argued that the outcome data suggests that ECT must be continued on a maintenance basis if symptomatic improvement is to be sustained. Kellner et al. (2006), for example, examined out-comes over six months of patients receiving a course of continuous ECT over a period of 6 months (shocks tapered from three times a week initially to monthly), either alone or in combination with pharmacotherapy. The authors concluded that both interventions “had limited efficacy, with more than half of patients either experiencing disease relapse or dropping out of the study”.