RESUMO
OBJECTIVE: Generalized anxiety disorder (GAD) is a common anxiety disorder. Although lots of research done to reveal neurobiological basis of GAD, it is still unclear. Diagnosis of GAD depends on subjective complaints of patients, thus the need for a biological marker is constantly emerging. In this study, we aimed to investigate diagnostic value of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) in GAD. METHODS: We evaluated MDA, SOD, and CAT levels in peripheral blood of 46 patients and 45 controls. MDA was measured with Ohkawa’s methods, SOD was measured with Fridovich method, and CAT was measured with Beutler’s method. RESULTS: MDA was significantly increased in patients than controls, medians 4.05 nmol/mg and 1.71 nmol/mg respectively, p < 0.001; SOD and CAT activity was significantly decreased in patients than controls, medians of SOD were 159.07 U/mg and 301.87 U/mg, p < 0.001 respectively, medians for CAT were 138.47 U/mg and 160.60 U/mg respectively. We found high correlation between Hamilton Anxiety Rating Scale and SOD, MDA r values were 0.723 and 0.715 respectively, p < 0.001 for both. Receiver operator characteristic (ROC) curve analysis showed high diagnostic performance for MDA and SOD, low diagnostic performance for CAT, areas under curve were 1.0, 1.0, and 0.648 respectively. CONCLUSION: Our results reveal possible diagnostic value of MDA, less likely of SOD but not CAT. Future studies should investigate diagnostic value of oxidants and antioxidantn enzymes in larger samples and include diagnostic value of these parameters.