IL6 and major depressive disorder: In addition, we found other studies that used the same depression scale than us (CES-D) [15,36] or a similar scale (PHQ-9) [16], and one of them found no association between clinical depression and the inflammatory marker IL-6 [36] or, similar to our results, two studies showed a negative association between depressive symptoms and hs-CRP [15,16] in multivariate regression analysis, after controlling for confounders.