“…Similarly, at variance with the positive results of FOULKS et al [436],5-HT also has proved to be of no value in the treatment of schizophrenia in the hands of several groups of investigators [237, 267, 691, 916dJ. In conclusion, there is as yet no convincing evidence that excess or deficiency of brain 5-HT, caused by a disturbed metabolism of the amine, may participate in the pathogenesis of schizophrenia, nor that 5-HTP or 5-HT may be of therapeutic benefit in the disease [134,396,650,648,400].…”