The thyrotropin-releasing hormone test in depressed and non-depressed psychiatric patients

Abstract

SummaryThe thyrotropin-releasing hormone (TRH) test was carried out in 231 depressed patients undergoing a dexamethasone suppression test (DST), and in 63 psychiatric control patients. The patients were classified according to DSM-III. Thyrotropin-secreting hormone (TSH) was determined in basal conditions, 20 and 60 min after the administration of 200 μg TRH. The Δ max TSH values (peak TSH response minus basal TSH) showed no significant difference between psychiatrie Controls and patients with major depression (296.00X2, 296.00X3, 296.00X4) or with depression (major and minor depression; 300,40, 296,82, 309.00). Consequently, the TRH test is not specifie either for depression or for major depression. Within the selected group of depressive patients, major depressives showed significantly (P<0.005) lower Δ max TSH responses than minor depressives. The TRH test could barely be used as a clinical diagnostic aid for major depression, since the predictive value for a positive test resuit was too low (maximal 70.2%). To separate major from minor depression, a single DST was more suitable than the TRH test or the combination of both tests. Age showed a negative correlation (P<0.005) with the Δ max TSH responses and could be considered as a predisposing factor for a blunted TSH response to TRH in depressive patients.