Role of oxidative stress in depression.

Reactive oxygen species (ROS) have vital roles in cellular signaling and in defence against invasive microorganisms. Excessive ROS generation and exhaustion of antioxidative defences trigger proinflammatory signaling, damaging vital macromolecules and inducing cellular apoptosis. The failure of cells to maintain redox homeostasis and resultant generation of proinflammatory mediators leads to cell necrosis. The brain is more vulnerable to oxidative stress (OS) because of its higher oxygen consumption, higher lipid content, and weaker antioxidative defence. OS is a main cause of neurodegeneration and its involvement in the pathogenesis of major depressive disorder (MDD) is unequivocally established. OS and proinflammatory signaling have emerged as mainstays in the pathogenesis of MDD. Targeting these changes with suitable antioxidants could be an effective strategy to treat MDD.