Plasma copper and dopamine-β-hydroxylase in schizophrenia

Patients were 32 chronic schizophrenics (20 men, 12 women; age range 18-32). Schizophrenic subjects had higher mean plasma copper levels than controls, although the difference was not statistically significant. There was a significant sex difference in both patients and controls with males displaying lower copper values than females. The finding of elevated plasma copper in drug-free schizophrenics and the reproducibility of copper levels over time regardless of clinical state indicate that neuroleptics do not play a major role in altering copper concentration and that copper levels are a state-independent characteristic of the individual. Several hypotheses linking copper to the biology of schizophrenia can be advanced. Changes in copper-dependent DBH activity have been claimed to modify central neurotransmitter metabolism. However, the correlation between DBH and copper levels was not found to be significant.