Triiodothyronine, thyroxine, and TSH response to dexamethasone in depressed patients and normal controls

In view of recent investigations concerning alterations of thyroid function in depression, the pre- and postdexamethasone levels of T3, T4, and TSH of 14 patients during depression and after recovery were studied, in addition to those of 27 healthy controls. A reduction of T3 and TSH levels was shown to be dependent on the depressive state, with a tendency to lower T4 levels after recovery. Dexamethasone had a pronounced suppressive effect on TSH levels in healthy controls and in patients after recovery, but not during the depressive episode. These results point to an inadequate suppressibility of the hypothalamo-pituitary-thyroid (HPT) axis to dexamethasone during depression. There are close interrelations between the hypothalamo-pituitary-adrenal (HPA) and the HPT axes that are possibly affected during depressive illness.

Insulin-like growth factor I in depressed patients and controls

To explore the role of the somatomedin-mediated long-loop negative feed-back mechanism in altered growth hormone (GH) secretory dynamics associated with depression, plasma IGF-I concentrations were measured in 34 patients with a major depressive episode and matched healthy subjects. Compared with controls, depressed patients exhibited significantly increased plasma IGF-I concentrations. In the patient group plasma IGF-I concentrations were positively correlated with the maximum post-dexamethasone plasma cortisol concentrations. Our data suggest that increased plasma IGF-I concentration may reflect diurnal GH hypersecretion, contribute to deficient GH responses to dynamic challenges, and indicate an interrelationship between the hypothalamic-pituitary-somatotropic (HPS) and -adrenocortical (HPA) system regulation in depression.

Gonadal steroid and gonadotropin response to dexamethasone: a study in sexual dysfunction and normal controls

Numerous investigations have reported an alteration of hormonal response to dexamethasone in depressive disorder. No such data are available in psychogenic sexual dysfunction. Pre- and postdexamethasone levels of testosterone, estradiol, LH and FSH were studied in 20 male patients with sexual dysfunction and 20 male healthy controls. Dexamethasone had no influence on testosterone, estradiol, LH and FSH in normal controls. The patients showed an increase in testosterone and LH but not in FSH levels in the morning after dexamethasone administration. When compared with basal levels, the increase in postdexamethasone levels in sexual dysfunction was significant for testosterone (delta T) but not for LH (delta LH). The altered gonadal steroid and gonadotropin response to dexamethasone in sexual dysfunction might be due to disturbances of dexamethasone metabolism and glucocorticoid receptor density comparable to similar findings in depressive disorder.

[Correlations between clinico-psychiatric findings and the dexamethasone suppression test in depression]

A study on 50 patients with endogenous and non-endogenous depression yielded a sensitivity of 64% and a specificity of 77% for the dexamethasone suppression test (DST). Endogenous depressive patients recovering from depression within one week mostly showed sufficient cortisol suppression. "Loss of feelings" was associated more frequently with cortisol nonsuppression, while a certain relationship between psychogenic induction of the present depressive episode and adequate suppression could be demonstrated. In conclusion, the diagnostic utility of the DST is of minor importance. However, in certain cases the DST could be recommended as a predictor of clinical course.

Factors interfering with the 1 mg dexamethasone suppression test in depression

The 1 mg dexamethasone suppression test (DST) was performed in 50 depressive inpatients in order to investigate factors which might interfere with its sensitivity and specificity for endogenous depression: improvement within one week after the test, recent admission to a psychiatric ward, and weight loss. Four out of five endogenous depressive patients whose depression improved within one week after the test had normal suppression, thus supporting the assumption that normalization of the DST may precede the improvement in depression. Nonendogenous depressive patients had an accumulation of pathologic test results on the day after admission that may be due to "admission stress". However, in endogenous depressives this effect was not observed. An influence of weight loss on the percentage of suppressors and nonsuppressors was not demonstrable. It is concluded that in the evaluation of DST results time parameters should be considered to a greater degree.

Prolactin response to dexamethasone: a study on normal controls and depressed patients

Pre- and post-dexamethasone prolactin and cortisol levels of 40 endogenous and non-endogenous depressive patients and of 20 controls were studied. Dexamethasone had a suppressive effect on prolactin levels, which was expressed more in normal controls and in non-endogenous depressive patients than in endogenous depression. A "prolactin suppression test" by dexamethasone was constructed and provided comparable results to the usual DST. However, it failed to be a specific marker for endogenous depression. There are close relationships between various endocrine axes, which might be altered in depression.