[Statistical versus clinical equivalence; the effectiveness of non-invasive neurostimulation in depression]

There is increasing interest in the use of non-invasive neurostimulation in the treatment of depressive disorder. A recent meta-analysis compared different forms of neurostimulation, and concluded that the effectiveness of different forms of this therapy, for example repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS), was similar to electroconvulsive therapy (ECT). In this comment we discuss these different techniques; we also stress that an unfair comparison has been made between the different forms of neurostimulation. In daily practice, techniques such as ECT, rTMS, and tDCS are used in different patient groups. ECT, in particular, is highly effective in patients suffering from a major depressive disorder with psychotic features, but this patient group has not been sufficiently included in the studies incorporated with a consequent negative bias towards ECT in this meta-analysis.