Pituitary response to TRH in bulimia.

The response to thyrotropin-releasing hormone (TRH) of thyroid-stimulating hormone (TSH), growth hormone (GH), and prolactin (PRL) was examined in nine normal weight female bulimics without endogenous depression and eight female controls. Four bulimics had delayed peak TSH response, but none demonstrated a blunted TSH response, unlike that which has been reported in endogenous depression. Bulimics had elevated mean +/- SD serum GH levels (controls 1.6 +/- 1.4 ng/ml, bulimics 5.6 +/- 3.9) and an inappropriate GH release following TRH. Their mean +/- SD serum PRL (3.1 +/- 1.7 ng/ml) was lower than that of controls (4.7 +/- 1.3); however, the PRL response to TRH was significantly greater in bulimics than in controls. These data show that neuroendocrine abnormalities exist in normal weight bulimic women without endogenous depression and provide further evidence for a neuroendocrine component to this illness.