CAT and major depressive disorder: In CUMS-induced depressed mice, the synthesis of peroxides such as MDA increased and the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased (Cheng et al., 2018), and antidepressant drugs could increase the levels of antioxidant enzymes, including catalase (CAT), SOD, and GSH-Px, in depressed patients or animals (Sherkawy et al., 2018; Meejuru et al., 2021; Mishra et al., 2021), the above suggests that improving the oxidative stress state might be an important direction for the treatment of depression.