Human growth hormone (HGH) responses to insulin-induced hypoglycemia were measured in ten postmenopausal women suffering from primary unipolar depressive illness, and in ten age-matched normal postmenopausal women. The mean maximal HGH response in the depressed patients was 4.6 ± 4.4 ng/ml, and in the normals 13.3 ± 9.8 ng/ml (P <.05).
All of the normal subjects had clinically adequate HGH responses, in contrast to only four of the depressed patients (P <.01). The blood glucose responses were virtually the same in the two groups. Since brain catecholamines play a major role in mediating HGH responses to hypoglycemia, the findings are consistent with the hypothesis of diminished functional catecholaminergic activity in the depressed patients.