The administration to 5 chronic schizophrenic patients of BAS alone, of BAS and 5-HTP combined, and of BAS and 5-HTP in conjunction with Marsilid was not therapeutically useful. The fact that the patients did not react to the presumed increase in brain serotonin casts doubt upon the hypothesis that too little or too much serotonin is causally related to schizophrenia.BAS appears to be a monoamine oxidase inhibitor. The conversion of 5-HTP to 5-HIAA was thus prevented resulting in an accumulation of serotonin in urine.Abstract Teaser