IL6 and major depressive disorder: IL-6 an inflammatory cytokine is associated with the presence of mental health problems, such as depression or anxiety (O’Donovan et al., 2010; Trapero and Cauli, 2014; Raposa et al., 2015; de Baumont et al., 2019; Müller et al., 2019; Niraula et al., 2019), or internalization and externalization behaviors (Slopen et al., 2013; Tang et al., 2019).