Weekly monitoring of dexamethasone suppression response in depression: its relationship to change of body weight and psychopathology.

Weekly dexamethasone suppression tests (DST) were performed in 19 hospitalized patients with major depressive disorder, endogenous subtype, and who had an abnormal DST at admission. Depression scores (Hamilton Rating Scale) and weight changes were collected by investigators who were blind to the test results. Major findings were: (1) the DST gradually normalized 3-4 weeks prior to full resolution of clinical symptomatology; (2) weight loss was an important patient variable which may have contributed to false positive DST results; however, the positive correlation between changes in DST results and changes in depression scores in all our patients with or without weight loss suggests that psychopathological factors other than weight change participate in the development of dexamethasone resistance in depression; (3) the low dose (1 mg) version of the test requires careful control of minor medical disturbances, which can make the test result ambiguous. The data suggest that after resolution of some methodological issues the DST may serve as a valuable laboratory test to monitor clinical progress during drug treatment.