Efficacy and safety of transcranial magnetic stimulation for treating major depressive disorder: An umbrella review and re-analysis of published meta-analyses of randomised controlled trials

•The application of TMS for treating MDD is used widely despite concerns regarding the internal validity of the available meta-analytic evidence.•Meta-analyses are not always interpreted in light of heterogeneity despite this being a key objective of random-effects meta-analysis.•We used up-to-date statistical methods to re-analyse published meta-analyses of RCTs testing the effects and safety of TMS for treating MDD.•Our results suggest the effects and safety of TMS in treating MDD are likely lower in some populations than previous estimates suggested.•Future research should focus on tailoring TMS treatment to populations with MDD more likely to achieve clinically important outcomes.