IN STUDIES OF 24-hour urine specimens from schizophrenic patients1 it was observed that preceding exacerbations of their paychotic symptoms and throughout the entire period of behavioral worsening increased excretions of indole metabolites occurred. In general, the largest and most consistent increases were in tryptamine whether appearing spontaneously or evoked by methionine with a monoamine oxidase enzyme (MAO) inhibitor. Increases were less with total indole-3-acetic acid and least with 5-hydroxyindole acetic acid. These changes in behavior and urinary output occurred whether these patients were on placebo, receiving reserpine, or a MAO inhibitor. Pollin and associates2 reported the effects of feeding various amino acids to schizophrenic patients. There were no changes in behavior that could be attributed to the administration of only amino acids. However, when iproniazid phosphate (Marsilid Phosphate), a MAO inhibitor, was added, exacerbations of the schizophrenic symptoms were observed with