Measures of serotonin metabolism in anorexia nervosa.

Thirty-five consecutive attenders at a clinic specializing in anorexia nervosa were studied. All conformed to a DSM-III-R diagnosis for anorexia nervosa. In addition, 3 cases suffered from major depressive disorder and 9 from dysthymia. Blood from all patients was analysed for monoamine oxidase, serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), tryptophan and platelet paroxetine binding. Findings showed that blood 5-HT was higher than normal in all patient groups, and was highest in those having affective disorder with anorexia nervosa. However, of the patients with anorexia nervosa alone, a subgroup having greatest weight loss had blood 5-HT levels significantly below all other groups. Lack of significant changes in other parameters compared with normal subjects points to the possibility of abnormal 5-HT storage or release.