Dexamethasone suppression test as a predictor of drug treatment response

The possible predictive value of cortisol non-suppression by dexamethasone for therapeutic response to antidepressants was investigated both in "endogenous" and "neurotic" depression. Seventy-four female patients who fulfilled the RDC of Major Depressive Disorder (Study 1) and 44 female patients with the diagnosis of "Neurotic Depression" of ICD-9 (Study 2) were given DST and then treated with antidepressants, their clinical response being assessed after four weeks of drug treatment. Forty-three out of the 74 patients with Primary Major Depression were non-suppressor. The DST non-suppressors showed a significantly more frequent therapeutic response to maprotiline than to amitriptyline. DST suppressors, on the other hand, responded better to amitriptyline treatment than non-suppressors. In the neurotic depression group 23 patients were subclassified as Primary Minor Depression, and 52% of them showed non-suppressor response to DST. Twenty-one patients were diagnosed as Secondary Depression, with a history of chronic neurosis. One patient only (5%) was the non-suppressor. Patients with Primary Minor Depression showed good therapeutic response to antidepressants more frequently, than patients with Secondary Depression.