CD8A and major depressive disorder: On the other hand, depression is characterized by increasingnumbers of CD3+CD8+ T-suppressor/cytotoxic cells, adecrease in the immunoregulatory index and the immuneresponse suppression (Alperina et al., 2007; Devoino et al.,2009; Haroon et al., 2012; Felger, Lotrich, 2013; Idova etal., 2013).