Tryptophan-loading in schizophrenia and endogenous depression

In 95 schizophrenic patients, 20 endogenous depressed patients and 39 control subjects the level of plasma tryptophan was determined after oral load of L-tryptophan (50 mg/kg) in range of 3 hours. Among the groups quantitative and specially qualitative differences were observed in course of tryptophan. In the group of schizophrenic patients it is possible to exactly differentiate a subgroup with similar psycho-pathological symptomatic by means the course of tryptophan.