Efficacy and Tolerability of Low-Field Magnetic Stimulation for Treatment of Depressive Disorder: A Systematic Review and Meta-Analysis of Randomized Sham-Controlled Studies.

Low-field magnetic stimulation (LFMS) has shown promising results for treating depression in preclinical and clinical studies. No previous meta-analysis has investigated its effects on depression. The aim of this systematic review and meta-analysis is to identify, evaluate, and summarize the current evidence for the efficacy and tolerability of LFMS in patients with depressive disorder. PubMed, Embase, Scopus, and Google Scholar databases were systematically searched to identify eligible studies published until February 15, 2025. Review protocol was prospectively registered with PROSPERO (CRD420250650519). Meta-analyses using a random-effects model was conducted to calculate pooled estimates. Standardized mean difference (SMD) and odds ratio (OR) were calculated for continuous and categorical outcomes, respectively. Nine randomized controlled trials (RCTs) comprising 571 patients were analysed. Five RCTs (55.5%) had 'some concerns', and 2 (22.2%) had a 'high risk' of bias. A moderate treatment effect size (SMD=-0.61; 95% CI: -0.91 to -0.30; P <0.001) favouring LFMS for the treatment of depression compared with sham stimulation was obtained. LFMS was well-tolerated with no significant difference in the frequency of adverse events reported between LFMS and sham groups, except for a significantly higher risk of myalgia associated with LFMS (OR=2.69; 95% CI: 1.14-6.31, P =0.02). Certainty of evidence on GRADE was 'low' for the primary outcome. LFMS may be a safe and effective neuromodulation technique for adjunctive treatment of depression. There is a need to conduct more robust RCTs with larger sample sizes, longer follow-up durations, and standardized LFMS stimulation parameters to better characterize its safety and efficacy.