Schizophrenia, Psychosis, and Cerebral Spinal Fluid Homovanillic Acid Concentrations

Neuroleptic drugs block brain dopamine receptors and are effective in treating psychoses of diverse origins. This finding has become a cornerstone of the dopamine theory of schizophrenia, but clinical studies relating schizophrenia, per se, to brain dopamine metabolism have ranged from controversial to negative. This article presents new evidence that cerebrospinal fluid levels of the dopamine metabolite homovanillic acid are related to the severity of psychosis in schizophrenia. These results support the concept that homovanillic acid levels in cerebrospinal fluid vary as a function of psychosis rather than being related to the diagnosis of schizophrenia per se.