TNF and major depressive disorder: Higher levels of IL-6 (Coef = 1.33, p < .001) and IL-8 (Coef = 0.69, p = .025) were associated with more frequent depressive symptoms while higher levels of TNF-α (OR = 2.50, p = .002), IL-1β (OR = 1.98, p = .001), and IL-8 (OR = 2.44, p = .008) were associated with greater odds of meeting criteria for clinical depression.