Thirty-four hour dexamethasone suppression test in depression

The utility of extending the dexamethasone suppression test past its usual 24 hr period to include a cortisol determination at 34 hr was investigated in 18 depressed patients. Conventional suppressors and non-suppressors differed significantly on their 34 hr cortisol values. However, this difference was small. Furthermore, 34 hr values generally returned close to baseline values, so that the 34 hr DST cannot now be recommended in the assessment of depressed patients without further study.