Reduced PON1 enzymatic activity and increased lipid hydroperoxide levels that point out oxidative stress in generalized anxiety disorder.

In recent years, there has been an increasing focus on generalized anxiety disorder (GAD) which is one of the most prevalent mental disorders in general population. Psychological, genetic, neurobiological, and neurochemical factors are believed to play role in the etiopathogenesis of GAD. The role of oxidative stress, as a neurochemical cause, in various anxiety disorders has been studied in recent years; however, it has not been thoroughly studied in GAD, yet. In this paper, we aimed to evaluate the serum levels of lipid hydroperoxide (LOOH), paraoxonase, and arylesterase in GAD patients without any co-morbid psychiatric disorders and investigate their diagnostic performance. Blood samples were collected from 40 GAD patients and 40 healthy control subjects to measure their serum LOOH levels, arylesterase and paraoxonase activities. Obtained results have been compared between groups and receiver operating characteristic (ROC) curve has been drawn for diagnostic performance of measured biochemical markers. Positive and negative predictive values have been estimated where appropriate. Mean LOOH level of the GAD patients was significantly higher than that of control subjects (t=-5.49, p<0.001), whereas, mean paraoxonase activity was lower in these patients (t=3.056, p=0.03). GAD could be predicted for LOOH level over 7.740 μmol/l with 92.5% positive predictive value and 92% negative predictive value. Increased LOOH level and decreased paraoxonase activity of GAD patients may suggest increased lipid peroxidation and oxidative stress in these patients. LOOH levels may be a state marker for diagnosing GAD.