Psychiatry Research EG

The response to the Dexamethasone Suppression Test (DST) was examined in 543 patients suffering from major depressive illness and 246 healthy controls from 13 research centers, from 12 different countries in a World Health Organisation Collaborative Study. In almost all the centres, the postdexamethasone plasma cortisol concentration was significantly higher in patients than in controls.
There were large and significant variations in DST between centres, which were not related to variables such as age, sex and severity of illness. These factors, however, had a modest, but clinically nonsignificant contribution to the variation in DST results in the whole population of patients.