TNF and major depressive disorder: Finally, in Model 4, the association between IL-6 levels and FAB score was also significant after adjustment for age (β = −0.17; 95% CI: −0.19 to −0.14), sex, educational level (β = 0.41; 95% CI: 0.37 to 0.45), BMI, LDL Cholesterol, AST, RBC, depression (β = −0.77; 95% CI: −1.21 to −0.33), CRP and TNF-α.