How Far Has Repetitive Transcranial Magnetic Stimulation Come Along in Treating Patients With Treatment-Resistant Depression?

Antidepressant drugs have been the mainstay for treating patients with major depressive disorder. However, with a rapid rise in the rates of major depressive disorder, there has been a substantial increase in the resistance to antidepressants in the last decade. This has augmented the need for alternative treatment modalities, including repetitive transcranial magnetic stimulation. This review assesses the progress repetitive transcranial magnetic stimulation has made in treating patients resistant to antidepressants. We conducted a comprehensive literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The clinical studies reviewed under the scope of this paper showed significant benefits in treatment-resistant patients. Several studies demonstrated that the prefrontal cortex's unilateral and bilateral transcranial magnetic stimulation increased the remission rates in active treatment groups compared to the control. Treatments ranged from 10 to 20 sessions, with 1,600 pulses to a maximum of 4,000 pulses in unilateral stimulation and 720 to 2,100 pulses in bilateral stimulation per session. Interestingly, bilateral stimulation utilizing fewer pulses showed notable improvement than a higher number of pulses in unilateral stimulation. However, the lack of standardized dose, dosing frequency, treatment duration, and follow-up protocols warrant further research to bring this therapy into clinical practice.