The authors examined the relationship of clinical variables, family history, and neuroendocrine function in 18 bulimic patients. Twelve of 18 patients (67%) showed abnormalities of cortisol suppression, and 8 of 10 (80%) showed blunted thyrotropin-releasing hormone (TRH) tests. These findings suggest that neuroendocrine abnormalities identified previously in anorexia nervosa are not solely an artifact of low weight and, further, that eating disorders and affective disorders may share neurochemical similarities.