L-5-hydroxytryptophan attenuates positive psychotic symptoms induced by D-amphetamine.

ABSTRACT

Brain serotonin has been hypothesized to be involved in the modulation of psychotic symptoms in at least some forms of schizophrenia. We examined the effects of the serotonin precursor L-5-hydroxytryptophan (5HTP) on D-amphetamine induction of acute psychotic symptoms in schizophrenic patients. Preadministration with 5HTP significantly antagonized amphetamine-elicited elevations in thought disturbance, activation, and hallucinations.