IL6 and major depressive disorder: Studies examining the links between inflammation and depression including meta-analyses of case/control studies (e.g.(Osimo et al., 2020)), RCTs (e.g.(Hannestad et al., 2011)), longitudinal studies (e.g. (Khandaker et al., 2014) and cross-sectional studies (e.g. (Anderson et al., 2022; Milaneschi et al., 2021a)) have reported associations between inflammatory markers e.g. CRP, IL-6, TNF-alpha and even markers of macrophage activation (Anderson et al., 2022; Postal et al., 2016; Ye et al., 2021; Zalli et al., 2016) and depression.