Abstract

Introduction: Reactive oxygen species (ROS) may play a role in some neuropsychiatric disorders. There is some evidence that the activation of immune-inflammatory processes, an increase in monoamines catabolism and abnormalities in lipid compounds may cause overproduction of ROS and lipid peroxidation. These phenomena may be related to pathophysiology of major depressive disorder and generalized anxiety disorder. Malondialdehyde (MDA) is the end product of lipid peroxidation. Vitamin E is thought to play an important role as an antioxidant against lipid peroxidation.
This study aims to investigate the role of oxygen radicals in the etiology of major depressive disorder and generalized anxiety disorder.

Method: Plasma MDA and vitamin E levels of patients with major depressive disorder (n=42) and generalized anxiety disorder (n=37) were compared with healthy controls (n=38). To assess depressive symptoms and anxiety symptoms, Hamilton Depression Scale and Hamilton Anxiety Scale were applied.

Results: Patients with major depressive disorder and generalized anxiety disorder had higher MDA and lower vitamin E levels than those of healthy controls. Differences between the patient and the control groups according to these two parameters were found statistically significant.

Conclusion: Our results support the hypothesis that oxidative stress may affect depressive and anxiety symptoms. As a result, free radical damage and deficiency of antioxidant defence systems may have an important role in major depressive disorder and generalized anxiety disorder.

Key words: Major depressive disorder, generalized anxiety disorder, oxidative stress, antioxidant defence systems