Normalisation of the dexamethasone suppression test: a correlate of clinical improvement in primary depressives.

Thirty-six patients with a primary depressive illness, admitted consecutively to hospital, were studied. All patients had a pre-treatment DST, followed by weekly DSTs during a six-week treatment period. Three categories of DST response were identified, on the basis of the serial DSTs. All three groups showed improvement with treatment: the two non-suppressor groups showed normalisation of the DST over the treatment period, but only the normalising nonsuppressors showed a significant correlation between DST normalisation and clinical improvement.