Introduction Recently, in the course of experiments dealing with intravenous infusions of epinephrine and norepinephrine in man,1occasion presented itself to perform infusions on a group of normal subjects and on a group of schizophrenic patients. It appeared that data concerning plasma concentrations of epinephrine and norepinephrine during infusions had bearing on recent suggestions that schizophrenia might be related to a faulty metabolism of either of these two substances. Hoffer and co-workers,2,3for instance, had presented evidence suggestive that certain oxidized derivatives of epinephrine, namely, adrenochrome (3-hydroxy-2,3dihydro-1-methylindole-5,6-quinone) and adrenolutin (3,5,6-trihydroxy-1-methylindole) were capable of producing transient psychoses and other mental aberrations in man when administered intravenously or orally. Thus, the view was advanced3that a defect in epinephrine metabolism resulting in the formation of excessive quantities of adrenochrome or adrenolutin might be an etiologic factor in schizophrenia. In support of this