When severe depression was used as the dependent variable and the same covariates were adjusted for, a statistically significant association was found with CRP (OR 2.21 [95% CI 1.29, 4.05]) and the generalised inflammation factor (OR 1.57 [95% CI 1.11, 2.23]), but not with fibrinogen (OR 1.34 [95% CI 0.73, 2.44]), IL-6 (OR 1.74 [95% CI 0.90, 3.25]) or TNF-α (OR 1.60 [95% CI 0.91, 2.82]). This evidence concerns the gene IL6 and major depressive disorder.