Using the IVW method, genetically proxied concentrations of IL-18, IL-1β, and reduced upon activation normal T cell expressed and secreted (RANTES) were found to be inversely associated with a increased risk of depression (OR = 0.968, 95%CI = 0.938, 0.998, p = 0.036; OR = 0.875, 95%CI = 0.787, 0.971, p = 0.012; OR = 0.947, 95%CI = 0.902, 0.995, p = 0.03; respectively). Here, IL18 is linked to major depressive disorder.