Insulin tolerance tests (ITTs) were performed after at least four months of sustained recovery from an episode of a major depressive disorder in 18 drug-free prepubertal children. Eleven had a definite endogenous subtype; seven did not. Sixteen children with nondepressed neurotic disorders made up a control group. The children with past endogenous depression continued to have significant hyposecretion of growth hormone (GH) in this test when compared with the other groups. Illness-recovery correlations were highly significant for the major depressive group as a whole. Paired comparisons of both depressive groups were not significantly different from illness to recovery. We conclude that prepubertal children with endogenous major depression continue to have hyposecretion of GH in response to ITTs in a recovered state and that this neuroendocrine marker Is state independent. A GH hyporesponse to ITT may be a true marker of a past episode or of trait for endogenous major depressive disorder in prepuberty.