Thyrotropin and Growth Hormone Responses to TRH Stimulation Are Normal in 6–12 Year-Old Children with Major Depression

Thyrotropin-stimulating hormone (TSH) and growth hormone (GH) responses to thyrotropin-releasing hormone (TRH) stimulation were examined as potential biological markers of childhood depression in 20 drug-free children on a children's psychiatric unit. Six children fulfilled DSM-III-R criteria based on KIDDIE–SADS–E interviews for major depression (MD). The control group consisted of 14 children with other psychiatric disorders. TSH and GH were measured before and over the course of 90 minutes after administration of TRH (400 μg i.v.). There were no significant differences between children with major depression and children with other psychiatric disorders in TSH or GH response to TRH stimulation, as measured by mean baseline levels, mean peak levels, mean change in levels (peak minus baseline), and mean time of peak levels. These results suggest that, unlike adolescents and adults with major depression, children with major depression do not demonstrate a blunted TSH response. Similarly, unlike adults with major depression, children with major depression do not demonstrate an elevated GH response to TRH stimulation. In its current form, the TRH stimulation test does not seem to be a useful procedure for the diagnosis of children with major depression. It is unclear why adults do, and children do not, show evidence of hypothalamic–pituitary–thyroid dysfunction during acute episodes of major depression.