TNF and major depressive disorder: Some studies have shown modified expression of microRNAs after antidepressant treatment.[17,18] Other studies have shown that inflammation in MDD is a factor that should be evaluated and understood and it is related to the increase of proinflammatory cytokines such as interleukin 1-beta (IL-1B), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-A), and interferon-gamma (IFN-G), among others.[19–21]