Abstract: | The thyrotrophin-releasing hormone (TRH) stimulation test is becoming useful in the diagnosis of depression, but the optimum concentration of TRH required remains uncertain. The test was performed on a carefully selected group of patients with primary unipolar major depressive episodes with melancholia, who were severely depressed, using TRH 200 micrograms and 500 micrograms (groups 1 and 2). The thyroid-stimulating hormone (TSH), growth hormone (GH) and prolactin (PRL) levels were measured in response to TRH. Responses obtained were compared with respect to hormonal and genetic subgroups. Comparing groups 1 and 2 revealed significant differences in the GH responses (P = 0,0059). A similar significant difference was found in the GH response (P = 0,0102) elicited by the women in each group. Comparison of the genetic subgroups of groups 1 and 2 revealed a significant difference in the PRL response of both the genetic spectrum (P = 0,0258) and the group without a genetic history (P = 0,0259) of alcoholism or depression. The TSH response in the genetic spectrum group was also significantly higher (P = 0,0008) in group 2. Further investigations of the responses elicited in the different genetic subgroups may reveal important variables for the investigation of the pathogenesis of depression. |