Influence of Weight Loss on the Dexamethasone Suppression Test

To the Editor.—  Nonsuppression of plasma cortisol in the dexamethasone suppression test (DST) is regarded as a highly specific marker for endogenous depression.^1,2 Weight loss in anorexia nervosa and in patients with severe protein-caloric malnutrition also causes DST nonsuppression.^3-5 Diminished appetite with resulting low caloric intake and weight loss is one of the most prominent symptoms of depressive illness.⁶ Therefore, it is worthwhile to consider how far weight loss may be responsible for DST nonsuppression in depressed patients. In a study with 20 endogenous, 19 neurotic, and six unclassified depressed patients with a comparable degree of severity of depression, the 1.5-mg DST was performed.⁷ Blood samples were taken at 9 AM and 4 PM after dexamethasone had been given orally at 11 PM.The DST results were abnormal (at least one cortisol value >5ug/dL) in five endogenous (25%) and four neurotic (21.1%) depressives, but in none