IL6 and major depressive disorder: Prior studies support a link between depression and inflammatory markers, including IL-1β, IL-2, and IL-6, contributing to depression as an independent CVD risk factor (Alesci et al., 2005; Danesh, Collins, & Peto, 1997; Dawood et al., 2007; Leo et al., 2006; Maes et al., 1995; Miller, Stetler, Carney, Freedland, & Banks, 2002; Saran, Puri, & Agarwal, 2012).