Central-Nervous-System Effects of Ingestion of L-Tryptophan by Normal Subjects

INTEREST in the action of monoamine oxidase inhibitors has focused attention on the effects that metabolites of naturally occurring amino acids may have on the function of the central nervous system. Lauer et al.1 found that combined therapy with tryptophan and iproniazid had more therapeutic effect on psychotic patients than iproniazid alone. Oates and Sjoerdsma2 showed that administration of tryptophan to subjects receiving monoamine oxidase inhibitors produced hyperreflexia, clonus and euphoria. Pollin, Cardon and Kety3 observed hyporeflexia and extensive mood changes in schizophrenic patients who received tryptophan, or methionine in addition to a monoamine oxidase inhibitor.In conjunction with preliminary . . .