TNF and major depressive disorder: Experimental studies have shown that stress is associated with elevated levels of CRP and TNF-α [2], that a stressful social family environment can directly stimulate the production of pro-inflammatory cytokines, and that changes in coagulation factors and genetic factors can increase the risk of depressive symptoms as well as cardiovascular diseases and glucose metabolism alterations, considering the theory that the inflammatory process is an etiological factor in depression associated with increased levels of inflammatory markers [3].