Studies have already pointed out the contribution of oxidative stress in the pathophysiology of major depressive disorder (MDD). The aim of the present study was to investigate the oxidative-antioxidative systems in MDD and in response to cognitive psychotherapies. Oxidative stress were analyzed in 49 MDD patients at baseline, post-treatment, and follow-up; and 49 control subjects without history of psychiatric disorders.
MDD subjects presented an increase in oxidative damage related to control subjects for thiobarbituric acid reactive species (TBARS), nitric oxide, and a decrease in total thiol content. Cognitive psychotherapies were able to counteract peripheral oxidative stress in MDD patients, reducing TBARS levels (p < 0.001) in the follow-up, nitric oxide (p < 0.001) in the post-treatment and follow-up, and increasing the total thiol content (p < 0.01) in the post-treatment and follow-up.
Oxidative stress was associated with MDD and the regulation of these parameters might represent an important mechanism associated with the clinical improvement of cognitive psychotherapy.