The dexamethasone suppression test in panic disorder.

The dexamethasone suppression test (DST) was performed in 35 patients with panic disorder and 21 normal control subjects. Non-suppression of plasma cortisol was determined as 4 micrograms/dl and using this figure 29% of panic patients and 9.5% of controls were non-suppressors. There was no significant difference in the number of suppressors and non-suppressors between patient and control groups (chi 2 = 1.81; P greater than 0.05). Both pre- and postdexamethasone cortisol concentrations were significantly different between the two groups possible indicating a cortisol hypersecretion in some panic patients.