PRESYNAPTIC DOPAMINE FUNCTION IN STRIATUM OF NEUROLEPTIC-NAIVE SCHIZOPHRENIC-PATIENTS

Presynaptic dopamine function (6-[F-18]-fluorodopa uptake) in the brai ns of seven neuroleptic-naive first-admission schizophrenic patients a nd eight healthy controls was studied with positron emission tomograph y. The fluorodopa influx constant (K-i) in putamen was higher in the p atients than in controls (average mean: 0.0149 vs 0.0129, p=0.034). Th e changes in caudate were smaller but significantly lateralised to the left caudate. There was one catatonic schizophrenic patient in our sa mple. This patient had lower striatal K-i than any control. Alteration s in striatal presynaptic dopamine function may constitute a part of d isrupted neural circuits that predispose to schizophrenic psychosis.