Endocrine studies on “Endogenous” Psychoses

II. Response of Plasma Grow th Hormone, Plasma Cortisol and Plasma ACTH to Various Kinds of Stimuli in Depressive Patients

Abstract

The insulin tolerance test (ITT), rapid ACTH test, dexamethasone test and metyrapone test were carried out serially on eleven depressive patients (four male and seven female, aged 12 to 60 years). Six of them were bipolar and five were monopolar.
Levels of plasma growth hormone (GH), plasma cortisol and plasma ACTH were determined by radioimmunoassay. Blood sugar levels were determined by autoanalyser.
Each patient undertook the same series of tests twice at two different clinical stages, i.e. during depression and after recovery. No drug was administered in four patients for more than three days before the beginning of each series of tests. The other seven were under the same medication at both clinical stages.
Results were as follows :
1) Blood sugar
Blood sugar response to ITT was almost identical and within normal range at both clinical stages.
2) Plasma Growth Hormone
The response of plasma GH to ITT in patients during depression was significantly lower than that of normal subjects. It also tended to be lower than that of patients after recovery, although the difference was not statistically significant. Mean GH response in patients to the rapid ACTH test also tended to be lower during depression than after recovery.
3) Plasma Cortisol
Mean basal levels of plasma cortisol of patients at 8 a.m. and 8 p.m. did not show any statistically significant difference from those of normal subjects. Every morning level was higher than the evening level, although during depression some patients had higher evening levels than normal. Some patients during depression also had insufficient suppression of plasma cortisol levels after dexamethasone administration. Response of plasma cortisol to ITT in patients was almost identical and within normal range both during depression and after recovery. Cortisol response to the rapid ACTH test during depression was significantly higher than that after recovery.
4) Plasma ACTH
No difference was found between basal morning plasma ACTH levels as well aslevels after metyrapone administration in patients during depression and after recovery. Each mean fell within normal range in both clinical stages.
No significant correlation was found between maximal GH levels and maximal cortisol levels during ITT and the rapid ACTH test in patients in depressive states.
The possible existence of complicated neuroendocrine and metabolic turmoil in depressive patients was discussed.