Low serum and urinary Cortisol has been a consistent finding in post traumatic stress disorder (PTSD). Glucocorticoid receptor numbers are increased. PTSD patients have a significantly lower adrenocorticotropic hormone (ACTH) in response to corticotrophin releasing hormone (CRH) when compared to a control group of normal volunteers. The dexamethasone suppression test exhibits an exaggerated suppression response of Cortisol to dexamethasone, when the dose utilised is lower than that utilised to test patients with depression. Increased urine levels of noradrenaline and dopamine has been noted in patients with PTSD. This is believed to be related to the hyperarousal state of PTSD.