Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression in Adult and Youth Populations: A Systematic Literature Review and Meta-Analysis.

BACKGROUND Between 30% and 60% of individuals with major depressive disorder will have treatment-resistant depression (TRD): depression that does not subside with pharmaceutical treatment. Repetitive transcranial magnetic stimulation (rTMS) is an emerging treatment for TRD. OBJECTIVE To establish the efficacy and optimal protocol for rTMS among adults and youth with TRD. DATA SOURCES Two systematic reviews were conducted: one to determine the efficacy of rTMS for adults with TRD and another to determine the effectiveness of rTMS for youth with TRD. For adults, MEDLINE, Cochrane Central Register of Controlled Trials, PubMed, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews, and Health Technology Assessment Database were searched from inception until January 10, 2014 with no language restrictions. Terms aimed at capturing the target diagnosis, such as depression and depressive disorder, were combined with terms describing the technology, such as transcranial magnetic stimulation and rTMS. Results were limited to studies involving human participants and designed as a randomized controlled trial. For youth, the search was altered to include youth only (aged 13-25 years) and all study designs. When possible, meta-analysis of response and remission rates was conducted. STUDY SELECTION Seventy-three articles were included in this review: 70 on adult and 3 on youth populations. RESULTS Meta-analysis comparing rTMS and sham in adults found statistically significant results favoring rTMS for response (RR: 2.35 [95% CI, 1.70-3.25]) and remission (RR: 2.24 [95% CI, 1.53-3.27]). No statistically significant differences were found when comparing high- and low-frequency, unilateral and bilateral, low- and high-intensity rTMS or rTMS and electroconvulsive therapy (ECT). While meta-analysis of results from the youth literature was not possible, the limited evidence base suggests that rTMS may be effective for treating TRD in youth. CONCLUSIONS The evidence available on the use of rTMS for adults with TRD indicates that rTMS is approximately twice as effective as a sham procedure, although the optimal rTMS protocol remains unclear. Evidence also indicates that rTMS is as effective as ECT and appears promising as a treatment for youth with TRD; however, the evidence base is underdeveloped.