The TRH test in bulimia and anorexia nervosa: a controlled study.

TSH responsiveness to 500 micrograms TRH given intravenously was examined in ten bulimic outpatients, nine anorexic in-patients and a group of age matched healthy subjects. Serum TSH levels were measured by means of a sensitive radioimmune assay. There were no group differences between bulimic subjects and the healthy comparison group. Anorexic subjects at low weight showed a delayed response to TRH, which tended to normalize with weight gain. Bulimic subjects showed varied patterns of response and it remains possible that a sub-group of bulimic patients may have an abnormality of response to TRH.