Thyroid function and response to 48-hour sleep deprivation in treatment-resistant depressed patients

Background: Clinical depression is associated with abnormalities of the hyp othalamic-pituitary-thyroid axis. Changes in thyroid function during sleep deprivation may be related to its antidepressant effects. Methods: Levels of thyroid-stimulating hormone, triiodothyronine, tri-iodot hyronine uptake, thyroxine, and free thyroxine were measured before, during , and after a 48-hour sleep deprivation in nine treatment-resistant de pres sed patients, Clinical state was assessed every 4 hours. A retrospective st udy of 26 similar patients was added for cross-validation. Results: Significant increases in thyroid-stimulating hormone and tri-iodot hyronine during sleep deprivation were not correlated with clinical improve ment. Sleep deprivation responders had lower tri-iodothyronine uptake level s than nonresponders in both the prospective (p < .02) and the retrospectiv e (p < .03) samples, Conclusions: The lower tri-iodothyronine uptake values in responders may id entify, a subgroup of depressed patients who respond to sleep deprivation b y virtue of some abnormality of the hypothalamic-pituitary-thyroid axis tha t is temporarily corrected by sleep deprivation. (C) 2000 Society of Biolog ical Psychiatry.