GPX4 and major depressive disorder: Studies have found that acupuncture can effectively reverse the CUMS-induced decline in Nrf2, HO-1, and GPX4 levels in the hippocampus of rats, reduce the activation of astrocytes and microglia, and alleviate depression-like behavior induced by CUMS.642 Ketamine may also have a rapid antidepressant effect by increasing FTH1 and GPX4 levels, and reducing TFR1 levels, which in turn inhibits ferroptosis.643