Dopamine-beta-hydroxylase deficits in the brains of schizophrenic patients

Postmortem brain specimens from 18 schizophrenic patients and 12 normal controls were assayed for dopamine-beta-hydroxylase (DBH), the enzyme responsible for the final step in norepinephrine biosynthesis. There was a significant reduction in the DBH activity of the schizophrenic group in all brain regions examined. Enzyme deficits in hippocampus and diencephalon were somewhat larger than that in pons-medulla. Since various extraneous factors, such as non-specific deterioration, drug treatment, duration of hospitalization, cause of death, sex, and age could be ruled out, the deficits in DBH mnay be associated with the schizophrenic disease process. These findings are consistent with the hypothesis that noradrenergic "reward" pathways are damaged in schizophrenia.