Neuroendocrine challenge tests in depression: a study of growth hormone, TRH and cortisol release

Thirty drug-free patients fulfilling the DSM-III criteria for major depression serially underwent the dexamethasone suppression test (DST), thyroid stimulating hormone (TSH) test and a growth hormone (GH) challenge test with oral desipramine. Fifty-three per cent of the sample showed a blunted GH response, 47% were DST non-suppressors while 26% had a blunted TSH response. Eighty per cent of patients showed some biological abnormality. There was no clear association between any of these abnormalities. Neither was there any association between the neuroendocrine parameters studied and the severity of depression or patient gender. There was a trend for increasing GH blunting and DST non-suppression with increasing age.