Repetitive Transcranial Magnetic Stimulation in Major Depressive Disorder: From Bench to Bedside—A Scoping Review of Neurobiological Mechanisms and Clinical Translation

Major depressive disorder (MDD) is one of the most prevalent mental illnesses and, despite the availability of multiple treatment options, remains difficult to treat for a substantial proportion of patients. Repetitive transcranial magnetic stimulation (rTMS) is an important therapeutic approach for depression, modulating brain activity through targeted magnetic pulses in a non-invasive manner. This review examined scientific evidence from clinical trials, large-scale analyses, and laboratory investigations regarding the effectiveness and safety of rTMS, as well as its role within contemporary therapeutic strategies for depression. In addition to conventional rTMS, the review addresses theta-burst stimulation (TBS), deep TMS, and various approaches aimed at enhancing treatment efficacy or accelerating clinical response, while also discussing the practical utility of different stimulation devices. rTMS applied to specific regions of the prefrontal cortex has demonstrated significant antidepressant effects, and intermittent theta-burst stimulation (iTBS) appears to achieve comparable outcomes within a shorter time frame. Research further indicates that rTMS is associated with neurobiological changes in brain connectivity, modulation of neurotransmitter systems, and the promotion of neuroplasticity. Across studies, rTMS is generally considered safe, with reported adverse effects being mild and transient. However, further research is needed to optimize stimulation protocols, clarify medium and long-term effects, individualize treatment approaches, and determine the durability of therapeutic benefits.