Efficacy of repetitive transcranial magnetic stimulation in treatment-resistant depression: the evidence thus far

Depression is a common mental disorder, which attributes to significant morbidity, disability and burden of care. A significant number of patients with depression still remain symptomatic after adequate trials of antidepressant treatment as well as psychotherapy, which is often referred to as treatment-resistant depression. Neuromodulation techniques-like electroconvulsive therapy, vagus nerve stimulation, transcranial magnetic stimulation (TMS) and transcranial direct current stimulation, may be useful augmenting techniques in depression, mostly recommended for treatment-resistant cases. Robust evidence exists regarding the efficacy of electroconvulsive therapy in the management of treatment-resistant depression; however, other techniques are understudied. TMS has been increasingly studied in various psychiatric disorders including depression. It has been approved by the US Food and Drug Administration for use in major depressive disorder. Over the past two decades, TMS has been studied in diverse groups of the population with depression using several research designs. This article gives an overview of the efficacy of repetitive TMS in treatment-resistant depression with the recent evidence.