Growth hormone neurosecretory disfunction in major depressive illness

Neurotransmitter impairments in MDI can also affect hormonal neuroregulation. Therefore, we decided to study the integrated concentration of growth hormone (IC-GH) and its 24-h secretory profile in this pathology. Ten women with major depressive illness (MDI) (three premenopausal and seven postmenopausal) and four normal matched controls (one premenopausal and three postmenopausal) were evaluated. Samples were obtained every 30 min using a constant withdrawal pump. Growth hormone (GH) pulses were analysed by Cluster System. Twenty-four hour IC-GH was evaluated as area under the curve (AUC) and the following results were found: depressed (D) = 429.15 +/- 367.9 vs. controls (C) = 1281.07 +/- 379.77 (p < .008); nocturnal IC-GH: D = 220 +/- 274.0 vs. C = 739.52 +/- 378.15 (p < .02). No statistically significant differences were found between D and C in diurnal IC-GH or in the number of nocturnal or diurnal pulses. Adrenal (cortisol at 0800h, 2300h and post-suppression with 1 mg of dexamethasone) and thyroid (T3, T4, 0800h and 1700h TSH) evaluations did not show statistically significant differences between D and C women. In conclusion, patients with MDI present a decrease in total GH secretion at the expense of the nocturnal period, probably due to changes in the neurotransmitters that would be involved in depression.