CAT and hyperthyroidism: Both states of thyroid dysfunction (hyperthyroidism and hypothyroidism) promote oxidative damage in brain tissues displayed by elevated levels of MDA and NO concomitant with depletion of the enzymatic (SOD, CAT, and GPx) and non-enzymatic (GSH) antioxidants leading to brain damage (Ahmed et al. 2012; Farrokhi et al. 2014).