(I) mRNA expression of Cat (A), Gpx1 (B), Gpx4 (C), Nos2 (D) Kmo (E), Kynu (F) in PBMCs and (II) mRNA expression of CAT (A), Gpx1 (B), Gpx4 (C), Nos1 (D), Tph1 (E), Tph2 (F), Kmo (G), Kynu (H) in the brain structures (hippocampus, amygdala, cerebral cortex) of animals exposed to CMS for two weeks (control, stressed) and in animals exposed to CMS for seven weeks and administered vehicle (1 mL/kg) or escitalopram (10 mg/kg) for five weeks (control/esc, stressed/saline, stressed/esc). Relative gene expression levels were estimated using a 2−ΔCt (Ctgene–Ct18S) method. Data represent means ± SEM. n = 6. * p < 0.05, *** p < 0.001 stressed group relative to stressed/esc group; # p < 0.05 stressed group relative to control group; & p < 0.05, &&& p < 0.001 stressed/esc group relative to stressed/saline group.