TNF and major depressive disorder: Rodent models of depression (Zhao et al., 2018; Guan et al., 2020) have found similar increases in proinflammatory factors and proteins in the LHb, including tumor necrosis factor-a (TNF-a), C-reactive protein (CRP), and pro-inflammatory cytokines such as interleukin-1b (IL-1b), IL-6, and IL-10.