The authors evaluated 24 outpatients with panic disorder by means of the
afternoon continuous test for cortisol and the 1-mg dexamethasone
suppression test (DST) and compared the results with those of 38
outpatients with major depressive disorder and 61 healthy control subjects.
The mean basal cortisol level of the patients with panic disorder was
significantly higher than that of the normal control subjects but almost
identical to that of the depressed patients. Only three of the patients
with panic disorder had abnormal DST results. These results indicate that
patients with panic disorder have an abnormality of at least one function
of the hypothalamic-pituitary- adrenal system which overlaps the
abnormality in major depressive disorder.