Effects of repetitive transcranial magnetic stimulation therapy on weight and lipid metabolism in patients with treatment-resistant depression: A preliminary single-center retrospective cohort study

Aim: This study aimed to elucidate the effects of repetitive transcranial magnetic stimulation (rTMS) on weight, body mass index (BMI), and lipid metabolism in patients with treatment-resistant depression (TRD). Methods: This retrospective observational study included patients with TRD who received rTMS treatment at the Jikei University Hospital from September 2018 to August 2021. The patients were diagnosed based on the DSM-5 and ICD-10 criteria and treated using the NeuroStar TMS System. For 3–6 weeks, 10-Hz rTMS was administered to the left dorsolateral prefrontal cortex at 120% motor threshold. The primary outcomes were changes in weight and BMI, whereas the secondary outcomes included changes in total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol levels, thyroid function indicators, as well as HAMD-17, HAMD-24, and Montgomery–Åsberg Depression Rating Scale (MADRS) scores. Statistical analysis was conducted using paired t-tests and repeated measures ANOVA. Results: Among the 34 patients (20 men and 14 women) included, no significant changes were observed in weight or BMI after rTMS treatment (average weight reduction: −0.50 kg, 95% CI: −0.14 to 0.56, p = 0.24; average BMI reduction: −0.21, 95% CI: −0.10 to 0.61, p = 0.15). However, significant reductions in total, HDL, and LDL cholesterol levels and FT4 were observed. Furthermore, the HAMD-17, HAMD-24, and MADRS scores significantly increased post-treatment. Conclusion: rTMS treatment did not affect weight or BMI in patients with TRD but is believed to improve lipid metabolism.