TNF and major depressive disorder: The inflammatory process, when exacerbated, can cause a significant increase in the production and expression of proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and IL-1β, as well as reactive species of oxygen (ROS) and nitric oxide, contributing to the neuroinflammatory and neurodegenerative processes associated with psychiatric disorders, including MDD [11].