BackgroundBoth traditional and atypical antipsychotics have been hypothesised to be effective in schizophrenia through limbic and cortical D₂ dopamine receptor blockade.AimsTo investigate this hypothesis with the D₂/D₃-selective positron emission tomography (PET) probe [⁷⁶Br]-FLB457.MethodPETscans were performed on 6 controls and 18 patients with schizophreniatreated with haloperidol or with risperidone, clozapine, amisulpride or olanzapine.ResultsThe D₂ dopamine receptor blockade was high in the temporal cortex with both haloperidol and atypical antipsychotics. The atypicals, however, induced a significantly lower D₂ binding index than haloperidol in the thalamus and in the striatum.ConclusionsResults suggest that cortical D₂ dopamine receptors are a common target of traditional and atypical antipsychotics for therapeutic action. Higher in vivo binding to the D₂ receptors in the cortex than in the basal ganglia is suggested as an indicator of favourable profile for a putative antipsychotic compound.