THYROTROPIN RESPONSE TO THYROTROPIN-RELEASING-HORMONE IN RDC SCHIZODEPRESSED MEN

Biological tests may help clarify the relationships of schizoaffective disorder to both major depressive disorder and schizophrenia. Thyrotropin-releasing hormone (TRH), 500 .mu.g i.v., was administered to 14 schizodepressed, 23 schizophrenics, 41 unipolar major depressives (all by RDC) and 45 healthy controls, all males 20-67 years with no significant differences in age, body height or weight. Results showed no differences in maximal delta TSH (dTSH max) amongst schizoaffective depressed, schizophrenia and healthy control groups (10.1 .+-. 1.3, 9.2 .+-. 1.1, 9.7 .+-. 0.8 .mu.U/ml, means .+-. SEM respectively). Mean major depressives'' dTSH max was lower than in each of the other three groups (6.2 .+-. 0.4 .mu.U/ml, P < 0.01 for all). Utilizing a .ltoreq. 5.0 .mu.U/ml cut-off criterion for blunting, the schizodepressed had 36%, schizophrenics 44%, healthy controls 22% and major depressed 59% blunters (P < 0.05 from other three groups). Schizodepressed patients appeared significantly different from major depressed but closer to schizophrenics (and healthy controls) on the TRH test.