Lipid peroxidation and antioxidant protection in patients during acute depressive episodes and in remission after fluoxetine treatment

Increasing numbers of studies indicate that free radicals and their derivatives play a role in some neuropsychiatric disorders, such as depression. The aim of this study was to investigate the activities of antioxidant enzymes, lipid peroxidation and total antioxidant status (TAS) in patients suffering from major depressive disorder (MDD) as compared to healthy controls. Specifically,we wanted to estimate how fluoxetine influences antioxidant defense and lipid peroxidation.Fifty MDD patients and thirty healthy controls participated in the study. Antioxidant enzyme activities and lipid peroxidation levels were measured in erythrocytes, while TAS was measured in plasma. All measurements were taken during an acute depressive episode and then again during depression remission after a three-month fluoxetine treatment.During acute depressive episodes, patients had significantly higher activity levels of antioxidant enzymes, such as copper-zinc superoxide dismutase (SOD1) and catalase (CAT), as compared to healthy controls. Concentrations of malondialdehyde (MDA) were also significantly higher during depressive episodes. Activity levels of glutathione peroxidase (GPx) did not differ significantly between depressed patients and healthy control subjects. Moreover, the plasma total antioxidant status of the depressed patients was decreased in comparison to control subjects. After three months of fluoxetine treatment, the above parameters did not change significantly.Major depressive disorder is accompanied by disturbances in the balance between pro- and anti-oxidative processes; however, these disturbances do not improve in patients in remission after three months of fluoxetine therapy.