Growth hormone-releasing factor stimulation test in depression.

The authors administered the growth hormone-releasing factor (GRF) stimulation test to 19 patients with major depression and 19 age- and sex-matched control subjects to test the hypothesis that a blunted growth hormone (GH) response to clonidine reflects a central alpha 2-adrenergic receptor subsensitivity in depression. GH response to GRF was significantly higher in patients with depression than in control subjects. This group difference was mainly attributable to three of the 19 depressed patients who exhibited markedly high GH responses to GRF. These results suggest that the blunted GH response to clonidine seen in patients with depression is not due to a pituitary defect in GH secretion.