The authors studied pituitary thyrotropin, i.e., thyroid-stimulating
hormone (TSH), response to thyrotropin-releasing hormone (TRH) in patients
with primary affective disorder. There were no overall differences between
either depressed or manic patients and normal controls; however, the TSH
response was significantly lower in the unipolar depressed patients than in
either bipolar depressed patients or normal subjects. Bipolar patients in
the manic phase tended to have a lower response than bipolar depressed
patients. In the unipolar group, the TSH response showed a significant
negative correlation with the serotonin metabolite 5-hydroxyindoleacetic
acid (5-HIAA) in the CSF. These neuroendocrine responses may constitute
markers of specific monoamine dysfunction in subgroups of patients with
affective illness.Abstract Teaser