D-2 DOPAMINE-RECEPTOR BINDING IN THE BASAL GANGLIA OF ANTIPSYCHOTIC-FREE SCHIZOPHRENIC-PATIENTS - AN I-123 IBZM SINGLE-PHOTON EMISSION COMPUTERIZED-TOMOGRAPHY STUDY

We used SPECT to examine striatal D-2 receptor binding in 20 antipsychotic-free DSM-III-R schizophrenic patients and 20 age- and sex-matched normal controls. Dynamic single-slice SPECT, at a slice chosen to include the basal ganglia, began immediately following intravenous injection of 185 MBq of I-123-IBZM. A semiquantitative approach was used to generate indices of specific D-2 receptor binding in the basal ganglia. There was no overall elevation of D-2 receptor binding between patients and controls. A male sex-specific left lateralised asymmetry of striatal D-2 receptor binding was found in the patient group. Age-dependent decline of striatal D-2 receptors was confirmed in controls, but not in patients. These results suggest that alterations in striatal D-2 receptor distribution and density do occur in schizophrenia, and possibly reflect wider disruptions in prefrontal-striatal-limbic circuits.