Effects of antidepressant withdrawal on the dexamethasone suppression test

Withdrawal of antidepressant medications may be a source of variance in dexamethasone suppression test (DST) results. We investigated this issue retrospectively through the serial analysis of postdexamethasone plasma cortisol concentrations and clinical severity in 15 patients and 9 control subjects before, during, and after antidepressant withdrawal. Postdexamethasone cortisol concentrations were significantly higher during the antidepressant withdrawal phase. Drug-withdrawal subjects also had an increased frequency of DST nonsuppression. Recent withdrawal of antidepressants requires further study as a possible source of variance for hypothalamic-pituitary-adrenal measures.