Psychotropic drug withdrawal and the dexamethasone suppression test.

In a prospective study of 25 patients from the time of hospitalization, seven had recently discontinued psychotropic agents (including antidepressants, neuroleptics, and benzodiazepines). All seven had positive dexamethasone suppression test results after 1 week of hospitalization. This phenomenon did not occur in any of the other subjects who had not discontinued such medications. Some of the subjects with postdexamethasone cortisol increases reported drug discontinuation in the drug histories they gave at admission, but in three, drug screening provided the only evidence of prior drug use. Medication withdrawal may be an underappreciated confounding variable in DST studies.