These selected parameters were previously published, namely, the depression severity characterized by the CDI score [17], EPA and DHA levels, omega-6/omega-3 fatty acids ratio [17], thromboxane B, homocysteine and brain derived neutrophic factor (BDNF) [20] and oxidative tissue damage markers (lipoperoxides (LP), 8-isoprostane (8-IsoP), nitrotyrosine (NT), advanced oxidation protein products (AOPP), trolox equivalent antioxidant capacity (TEAC), Cu/Zn superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) [18]. Here, CAT is linked to major depressive disorder.