A revised interpretation of the TRH test results in female depressed patients. Part I: TSH responses. Effects of severity of illness, thyroid hormones, monoamines, age, sex hormonal, corticosteroid and nutritional state.
Thyrotropin secreting hormone (TSH) levels were recorded in baseline conditions and 20 and 60 min after thyrotropin releasing hormone (TRH) administration (200 micrograms i.v.) in 60 depressed females categorized according to DSM-III. Basal TSH (TSHB) and peak TSH responses (TSHP) were measured using ultrasensitive RIA assays. The use of delta max TSH (TSHP minus TSHB) had no advantage over the use of TSHP since both factors were almost linearly (r = 0.98) correlated. TSHP was largely (72% of the variance) predicted by TSHB. It was suggested that TSHP consisted of two components. The first part was a relative deduction from TSHB. The second part was the newly proposed concept of the residual TSH (TRHR). This part was computed by partialling out the relative effects of TSHB on TSHP by means of regression analysis. In clinical practice two relevant factors should be used to evaluate the hypothalamic-pituitary-thyroid (HPT) axis: (1) TSHB reflecting the setpoint of the HPT axis and (2) TSHR reflecting the latent capacity of the HPT axis to respond to overwhelming amounts of exogenous TRH. TSHB was significantly reduced in severely depressed patients (296.X3, 296.X4) as compared with minor depressives (300.40, 309.00). These differences could be attributed to significantly increased free thyroxine levels and to noradrenergic hyperactivity in the severely depressed females. TSHR correlated significantly and negatively with follicle stimulating hormone levels, age, body mass index and the post-dexamethasone cortisol values. TSHR was significantly reduced in the post-menopausal state.
Maes
M
M
Department of Psychiatry, University Hospital of Antwerpen, Edegem, Belgium.
Vandewoude
M
M
Maes
L
L
Schotte
C
C
Cosyns
P
P
D000328:Adult; D000368:Aged; D002395:Catecholamines / Q000097:blood*; D003866:Depressive Disorder / Q000097:blood / Q000175:diagnosis* / Q000523:psychology; D003907:Dexamethasone; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008875:Middle Aged; D011446:Prospective Studies; D011581:Psychological Tests; D011863:Radioimmunoassay; D013972:Thyrotropin / Q000097:blood*; D013973:Thyrotropin-Releasing Hormone
D002395:Catecholamines; D012739:Gonadal Steroid Hormones; D013973:Thyrotropin-Releasing Hormone; D003907:Dexamethasone; D013972:Thyrotropin; D006854:Hydrocortisone