The GH response to clonidine in endogenous as compared with reactive depression.

The growth hormone (GH) response to clonidine was measured in 10 patients meeting standardized criteria for 'endogenous' depression and in 10 patients individually matched for age and sex but meeting the corresponding criteria for 'reactive' depression. In a paired comparison of patients with reactive and endogenous depression (matched for age and sex), the GH response to clonidine was less in the endogenous member of the pair in 8 out of 10 cases. These findings are interpreted as evidence of a defect at alpha 2 adrenoceptors in neuroendocrine systems in endogenous as compared with reactive depression.