On the concentration of 5-hydroxyindoleacetic acid in schizophrenia: a meta-analysis

A meta-analysis was performed on the results of a number of investigations of concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid, serum, or urine of acute and chronic schizophrenic patients. Only those studies were chosen in which some degree of age and gender matching were achieved and in which the comparison subjects were healthy normal volunteers. Fisher's procedure and a weighted Liptak method revealed no significant differences between normal subjects and schizophrenic patients, indicating that disturbances of serotonergic turnover do not, in general or essentially, contribute to the etiology of schizophrenia.