CAT and major depressive disorder: They analyzed 44 studies, which included 1979 bipolar patients and 1788 healthy control patients, evaluating the following oxidative stress markers: SOD, CAT, GSH-Px enzymes, and TBA-RS levels during different phases of the disease (mania, depression, and euthymia), and separated them into subgroups (use and nonuse of mood-stabilizing drugs).