Decreased serum sulphydryl levels as a sign of increased oxidative stress in generalized anxiety disorder.

Objective: In recent years, many published studies have focused on the relationship between oxidative stress and psychiatric disorders. However, studies in generalized anxiety disorder (GAD) are few despite relatively high prevalence rates. In an attempt to fill this gap in the literature we aimed to measure serum levels of free sulphydryl, an important member of antioxidant defense mechanisms, of the patients with GAD.
Methods: A total of 35 (23 female, 12 male) GAD patients without any other co-morbid medical or psychiatric disorder and 35 (23 female, 12 male) healthy controls have been included in the study. Disease severity of the patients were quantified by using the Hamilton Anxiety Rating Scale (HAM-A). Serum free sulphydryl group levels of patients and healthy controls were measured in an appropriate way.
Results: Mean level of serum sulphydryl groups was significantly lower in the patient group. There was a negative correlation between their level and the disease duration. However, they did not show any significant correlation with the disease severity.
Conclusion: Decreased serum sulphydryl level observed in pure GAD patients suggests an increased oxidative stress in these patients. Well designed future researches are needed to replicate our findings and to test the implications of the present study.