IL6 and depressive disorder: Canonical pro-inflammatory cytokines, such as CRP, IL-1β, IL-6, and TNF-α, influence the central nervous system (CNS) function and contribute to changes in mood (Felger and Lotrich, 2013; Raison et al., 2006), social behavior (Jolink et al., 2022), emotion regulation (Appleton et al., 2013), and the onset and prognosis of depressive disorders (Khandaker et al., 2014; Osimo et al., 2020).