Clinical Significance of Transcranial Magnetic Stimulation (TMS) in the Treatment of Pharmacoresistant Depression: Synthesis of Recent Data

Transcranial magnetic stimulation (TMS) is a novel treatment for patients with major depressive disorder. Although clearly safer and better tolerated than many other pharmacotherapeutic options or electroconvulsive therapy, questions have persisted about the magnitude of the efficacy of TMS in patients with pharmacoresistant depression, and the clinical significance of these outcomes. Previous studies have explored whether specific patient characteristics are associated with a greater likelihood of clinical benefit. In the largest such analysis conducted to date, the authors confirmed previous observations that the lower the number of prior failed antidepressant treatments, the better the clinical outcome of treatment with TMS. This relationship between prior treatment resistance and subsequent treatment outcome is consistent with previous evidence from antidepressant studies. The authors examined the clinical significance of the treatment effects seen with TMS in pharmacoresistant major depression in their recently completed studies by comparing these outcomes with the results reported in several large, comprehensive published reference datasets of antidepressant medications studied in both treatment-responsive and treatment-resistant patient populations. The efficacy of TMS demonstrated in randomized controlled trials was comparable to that of pharmaceutical antidepressants studied in similarly designed registration trials and to the adjunctive use of atypical antipsychotic medications in controlled trials of antidepressant non-responders. These data may be helpful in treatment-planning decisions when using TMS in clinical practice.