Nocturnal Serum Thyrotropin (TSH) Surge and the TSH Response to TSH-Releasing Hormone: Dissociated Behavior in Untreated Depressives*

Abstract

TSH secretion, with particular regard to the nocturnal surge of the hormone, was evaluated in 15 women (age range, 35-66 yr; mean, 50 yr) with untreated major endogenous depression and 15 healthy women (age range, 32-67 yr; mean, 53 yr) using an ultrasensitive assay. Mean morning (0830 h) TSH values did not differ in the 2 groups (1.3 +/- 02 mU/L in depressives and 1.4 +/- 0.1 mU/L in controls), whereas mean nighttime (2400-0200 h) values were significantly reduced in depressives (1.5 +/- 0.3 vs. 3.1 +/- 0.3 mU/L; P less than 0.0005). At variance with the control group, morning and nighttime TSH values did not differ in the depressives. The nocturnal serum TSH surge was abolished in 14 of 15 depressed patients. The mean peak TSH value after TRH was slightly yet significantly lower in the depressives. Patients with subnormal (less than 0.4 mU/L) TSH values in the morning had a serum TSH increase after TRH less than 2 mU/L in 5 of 6 cases and a lack of the nocturnal TSH surge in 6 of 6. Among the 9 patients with normal TSH values in the morning, the nocturnal serum TSH surge was lost in 8 of 9, whereas the response to TRH was normal in all. The depressives, at variance with other reports, showed significantly lower values of total and free thyroid hormones. Mean serum sex hormone-binding globulin (SHBG) and ferritin were also significantly reduced. In conclusion, major endogenous depression is associated with a major impairment of TSH secretion, which baseline TSH measurements in the morning and the evaluation of the TSH response to TRH may not reveal. In this regard, the loss of the nocturnal serum TSH rise would appear to be a more sensitive indicator of hypothalamus-pituitary-thyroid axis alterations in depressives than the TRH test, which is commonly used in the evaluation of these patients. The lack of the nocturnal TSH surge may be responsible for the reduced thyroid hormone secretion and supports the case for some degree of central hypothyroidism in endogenous depression.

Subclinical hypothyroidism: neurobehavioral features and beneficial effect of l-thyroxine treatment

“…It may be modulated by several inputs (monoaminergic systems) themselves related to mood control and cognitive functions [20]. Currently available tests (serum TSH levels, TRH test) are unfortunately too gross to explore the hypothalamic-pituitary section, even though relevant alterations have been described both in bipolar disease and in major depression [3,12]. The above-mentioned neuropsychological and behavioral alterations bore no statistical relationship to TSH serum levels.…”

Association between serum ferritin concentrations and depressive symptoms in Japanese municipal employees

“…Significantly lower serum ferritin has been reported in non-anemic women with untreated major endogenous depression than in healthy controls (Batalena et al, 1990). In contrast, increased levels of serum ferritin concentrations were positively associated with depressive symptoms in studies conducted among inpatients admitted to the treatment resistant depression ward (Maes et al, 1996) and chronic hemodialysis patients with major depression (Huang and Lee, 2007).…”

Role of cytokines in the pathogenesis of the euthyroid sick syndrome

“…Serum thyrotropin (TSH) concentration is usually normal, although suppressed values may be found in a minority of patients (1). In addition, a decrease in the nocturnal surge of TSH has been consistently reported in patients with NTI (8)(9)(10)(11)(12). Abnormalities of TSH glycosylation causing its decreased biological activity were also described (13).…”