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.