Thyrotropin (TSH) and thyroid hormone concentrations during partial sleep deprivation in patients with major depressive disorder.

Thyrotropin (TSH), thyroxine (T4), free T4, triiodothyronine (T3), and free T3 (fT3) concentrations were measured in 25 patients with major depressive disorder at 8 a.m. both before and after partial sleep deprivation (PSD) during the second half of the night. Significant increases in TSH and T3 levels and a corresponding trend in fT3 levels were seen. No convincing correlations occurred between changes in the secretion of any of the hormones and the antidepressant effect of PSD. However, this does not rule out the possibility that the two phenomena, which occur in depression at different anatomical levels with presumably different degrees of disturbance in the respective receptor systems, have common underlying neurochemical mechanisms. Comparison of the effect of the PSD on changes in hormone secretion and mood with the corresponding effects in a sample of depressed patients who underwent total sleep deprivation showed no significant differences between the effects of these two forms of sleep deprivation on either variable.