The combined T3/TRH test in depressed patients and healthy controls.
It is well established that depressed patients show a blunted TSH response in the TRH-stimulation test. However, it has not been investigated so far whether pre-treatment with 3,5,3'-triiodothyronine (T3) is able to further suppress the TRH-induced TSH response in depressed patients or whether it may cause an escape-phenomenon with paradoxically enhanced TSH stimulation in a subsequent TRH test. In 20 drug-free depressed patients (eight men, 12 women) suffering from a major depressive episode according to DSM-IV criteria and in 20 age- and sex-matched healthy controls, the single TRH-stimulation test (administration of 200 microg TRH at 09:00 h) was carried out followed by a combined T3/TRH test (pre-treatment with 40 microg T3 at 23:00 h the night before; administration of 200 microg TRH at 09:00 h the next day). Compared to the controls, the depressed patients showed a significantly blunted TSH response in the single TRH test. However, the percentage suppression of TRH-induced TSH stimulation after pre-treatment with 40 microg T3 was comparable in the depressive patients (61.07%) and the healthy volunteers (64.20%). Prolactin secretion did not differ between patients and controls either in the single TRH test or in the combined T3/TRH test. Apparently, in contrast to the hypothalamo-pituitary-adrenocortical (HPA) system, no disturbance of feedback control in regulation of the hypothalamo-pituitary-thyroid (HPT) axis secretion can be demonstrated in depressed patients when using the combined T3/TRH test.
Schüle
Cornelius
C
Department of Psychiatry, Ludwig-Maximilian-University, Nussbaumstrasse 7, 80336 Munich, Germany. cornelius.schuele@med.uni-muenchen.de
Baghai
Thomas C
TC
Tsikolata
Vassiliki
V
Zwanzger
Peter
P
Eser
Daniela
D
Schaaf
Ludwig
L
Rupprecht
Rainer
R
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D003866:Depressive Disorder / Q000175:diagnosis* / Q000503:physiopathology; D004347:Drug Interactions; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006728:Hormones / Q000097:blood; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine; D014284:Triiodothyronine
D006728:Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine