IL6 and major depressive disorder: In 2022, Yi et al. developed a depressive mouse model by injecting lipopolysaccharide (LPS), and reported that LIFU to the prefrontal cortex significantly reduced inflammatory cytokine (including IL-6, IL-1β, and TNF-α) expression, improving depression and anxiety behaviors as assessed by behavioral tests such as the OFT, tail suspension test (TST), and elevated plus maze (EPM) [46].