Thyroid stimulating hormone response after thyrotropin releasing hormone in depressed, schizophrenic and normal women

(1) Thyroid stimulating hormone (TSH) response after injection of thyrotropin releasing hormone (TRH) was studied in 23 depressed, 9 schizophrenic and 40 normal women. (2) In no group was TSH response correlated with age. (3) In the depressed patients, no relationship was found between TSH response and (i) severity of illness, (ii) clinical subtypes (unipolar/bipolar) and (iii) clinical remission. (4) There were no statistically significant differences in TSH baseline values between the groups. (5) Neither of the two patient groups showed reliable differences from controls regarding TSH response. However, depressed patients tended to show lower values than controls, while schizophrenic patients tended to show higher values than normal controls. (6) Significant differences were found between depressed and schizophrenic patients in regard to TSH response. In three depressed patients a TSH response below 5 μU/ml was found. This deficient TSH response occurred in unipolar depressed patients and was not seen in bipolar depressed patients, schizophrenic patients or normal controls. (7) These data provide evidence for a fault in hypothalamic pituitary regulation in some depressed patients but not in schizophrenic patients.