Cerebrospinal fluid levels of homovanillic acid and 5-hydroxyindoleacetic acid in autism.

Cerebrospinal fluid (CSF) concentrations of the serotonin and dopamine metabolites, 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA), respectively, were measured in a group of 17 children with Autistic Disorder (DSM-III-R). The group means observed for 5HIAA (135 +/- 91 nmol/L) and HVA (502 +/- 324 nmol/L) in the autistic children were not significantly different from those seen in the control group of 15 nonneurologically impaired children (5HIAA, 122 +/- 120 nmol/L; HVA 401 +/- 378 nmol/L). These data suggest that consistent, marked alterations in central serotonin and dopamine turnover are not present in the autistic subjects studied. Although studies to date have found little or no alteration in CSF 5-HIAA in autism, the various reports of CSF HVA are not entirely congruent. Although this study is consistent with most previous studies in not finding a group difference in CSF HVA, the possibility of increased CSF HVA in autism cannot be ruled out.