Stimulatory tests of growth hormone secretion in prepubertal major depression: depressed versus normal children.
OBJECTIVE
Blunted stimulation of growth hormone (GH) secretion after pharmacological stimuli has been linked to depressive and anxiety disorders throughout the life span. This study sought to better characterize this dysregulation in prepubertal depression.


METHODS
GH regulation was compared in 38 medically healthy prepubertal children with current major depressive disorder and 19 control children who were medically and psychiatrically healthy. The study evaluated GH stimulatory responses to three pharmacological challenge agents: (1) insulin-induced hypoglycemia, using 0.1 IU/kg intravenous regular insulin; (2) 1.3 micrograms/kg intravenous clonidine; and (3) 1.0 microgram/kg intravenous human growth hormone-releasing hormone (GHRH).


RESULTS
The results provide replication and extension of earlier findings. GH responses to insulin-induced hypoglycemia and to GHRH stimulation were blunted in depressed children compared to the normal controls. Clonidine stimulation results yielded a similar picture but did not reach statistical significance.


CONCLUSIONS
Overall these results further strengthen the evidence showing GH dysregulation in childhood depression. However, the blunted GH response seen with GHRH (which reflects pituitary hyporesponsivity) was in contrast to our original hypothesis and has implications regarding the site (or sites) of dysregulation.
Ryan
N D
ND
Department of Psychiatry, University of Pittsburgh, PA.
Dahl
R E
RE
Birmaher
B
B
Williamson
D E
DE
Iyengar
S
S
Nelson
B
B
Puig-Antich
J
J
Perel
J M
JM
D000293:Adolescent; D002648:Child; D003000:Clonidine / Q000008:administration & dosage / Q000494:pharmacology*; D003866:Depressive Disorder / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000503:physiopathology; D007275:Injections, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010902:Pituitary Gland / Q000187:drug effects / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales
D007328:Insulin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D003000:Clonidine