The goals of this study are (1) to determine the IL-2,IL-4, IL-12, TNF-α, TGF beta-1 (TGF-β1),and monocyte chemotactic protein-1 (MCP-1) in our sample of depressed patients,(2) to evaluate whether these characteristics differ between patients withmajor depression and age- and sex-matched healthy controls, and (3) to investigatethe effect of treatment with, a selective serotonin reuptake inhibitor (SSRI)antidepressant, sertraline on these parameters. The gene discussed is IL2; the disease is major depressive disorder.