Growth hormone catecholamines in affective disease.

The authors studied growth hormone (GH) release after insulin-induced hypoglycemia (HI) in relation to urinary MHPG, the major metabolite of central norepinephrine. There was a significant linear correlation of urinary MHPG levels and GH peaks after HI in unipolar depressed patients and in manic patients; however, GH peaks in manic patients shifted downward on the GH axis in comparison to the unipolar depressive patients. The authors suggest that such shifts in the GH response may occur as a result of abnormalities of other neurotransmitter systems also known to facilitate GH release.