Dexamethasone Suppression Test
Dexamethasone is a synthetic glucocorticoid and acts as a ligand of glucocorticoid receptors. The principle of the dexamethasone suppression test (DST) is based on this binding capability. Via receptor binding, dexamethasone exerts a negative feedback function on the hypothalamus-pituitary-adrenal (HPA) axis (de Kloet et al. 1998). The HPA axis is a hierarchical hormonal system encompassing the hypothalamus, the pituitary gland, and the adrenal cortex with their respective hormones CRH, ACTH, and cortisol. Beside its role in stress regulation, the HPA axis is vital for supporting normal physiological functioning. Its functioning is controlled by several negative feedback loops. Generally, the DST is applied as a standard diagnostic tool to assess feedback sensitivity of the HPA axis in clinical settings (e.g., in major depression, posttraumatic stress disorder, etc.) as well as in...