For example, the Hedges effect size of IL-6 and TNF-α differences from baseline to 24 h after IFN-α are 0.48 and 0.66, respectively, which are very close to the difference between controls and patients with depression for these two cytokines, as shown by Hedges g = 0.62 and 0.68, respectively62. This evidence concerns the gene TNF and major depressive disorder.