The comparisons of effect sizes for serum TAC (A), serum non-enzymatic antioxidants (B), red blood cell enzymatic antioxidants (C), serum enzymatic antioxidants (D), serum free radicals (E) and serum oxidative damage products (F) in acute episodes between depressed patients and controls (red bar) and in comparison before and after treatment of depressed patients (yellow bar).

<p>Positive effect sizes (bars go upwards) indicate that the marker levels in depressed patients were higher than controls or increased after antidepressant therapy; negative effect sizes (bars go downwards) indicate that marker levels were lower than controls or decreased after antidepressant therapy. *<i>p</i> < 0.05, **<i>p</i> < 0.01, ***<i>p</i> < 0.001. TAC, total antioxidant capacity; HDL-C, high-density lipoprotein cholesterol; SOD, superoxide dismutase; GPX, glutathione peroxidase; CAT, catalase; GR, glutathione reductase; PON, paraoxonase; MDA, malondialdehyde; 8-<i>iso</i>-PGF_2α, 8-F2-isoprostanes; PCC, oxidation protein product.</p