Dopamine metabolism increases in post-mortem schizophrenic basal ganglia

The dopamine-rich regions of post-mortem brains from 6 schizophrenics and 7 controls were analyzed. There were no significant changes in dopamine concentrations in basal ganglia and nucleus accumbens of schizophrenics compared with controls. Schizophrenic basal ganglia (putamen and caudate) showed significantly higher levels of homovanillic acid, and tyrosine hydroxylase activity. Among the schizophrenic patients, markedly high activity of tyrosine hydroxylase was measured in a patient diagnosed as catatonic type. He had not taken antipsychotic drugs for 3 months prior to death. In his relatives, three other schizophrenics were found to the second degree. A remarkable low level of dopamine and a high level of homovanillic acid measured indicate this case would have had an increased turnover rate of dopamine in the dopaminergic nerve terminals. Among the schizophrenic patients, there might be one group whose enzyme activity of dopamine synthesis in the brain is exceptionally high.