AIMS:

To compare plasma and red-cell selenium concentrations of schizophrenic patients treated with clozapine, with healthy controls and patients with mood disorders.

METHODS:

Plasma and red-cell selenium concentrations were measured in random venous blood samples from four groups: mood disorder (n = 36), schizophrenics treated with clozapine (n = 54), schizophrenics not treated with clozapine (n = 41) and a healthy control group (n = 56). Assays were performed by an independent laboratory that was blinded to the patient groups and specializes in estimating trace metal concentrations.

RESULTS:

Selenium concentrations in plasma and red cells were found to be significantly lower in schizophrenic patients treated with clozapine as compared with all other groups.

CONCLUSIONS:

Selenium is an essential antioxidant. Its deficiency has been implicated in myocarditis and cardiomyopathy. Low selenium concentrations in clozapine-treated patients may be important in the pathogenesis of life threatening cardiac side-effects associated with clozapine. Further clinical studies are being conducted to explore this important clinical observation and its therapeutic implications.