Evaluation of hypothalamo-pituitary-adrenal axis activity by using dexamethasone suppression test in patients with panic disorder and generalized anxiety disorder -

Objective: The aim of this study was to investigate the role of hypothalamo-pituitary-adrenal (HPA) axis activity on the pathophysiology of anxiety disorders by examining the HPA axis activity in patients with panic disorder (PD) and generalized anxiety disorder (GAD). Method: Baseline and post dexamethasone suppression test (DST) serum concentrations of cortisol and dehydroepiandrosterone-sulfate (DHEA-S) were measured in patients with PD (n=24), GAD (n=21) and in healthy controls (n=20). Results: The baseline cortisol levels in GAD group were found lower than those of the patients with PD and healthy controls. Cortisol suppression by dexamethasone in GAD group was found to be lower than PD patients and healthy controls. Baseline and post-DST DHEA-S levels in the patients with PD and GAD were similar to those of the healthy controls. Conclusion: Lower cortisol levels and inadequate cortisol suppression with DST in GAD patients may suggest a downregulation in both corticotropin releasing hormone and glucocorticoid receptors in the central nervous system.