Schizophrenia affects about 1% of the population worldwide. 1 The onset of symptoms is generally in the late teens to early twenties. There is no cure for the disease, and current therapies have numerous, debilitating side effects. The combination of early onset of chronic disease and problematic therapies results in high costs for the patient, his or her family, and society at large. 2 While the etiology of schizophrenia remains unknown, several lines of research point to the dopaminergic system, 3 and, in particular, the dopamine D 4 receptor, as important in schizophrenia and psychotictype diseases in general. 4 Classical antipsychotics such as haloperidol, though effective in treating certain schizophrenic states, cause extrapyramidal side effects and tardive dyskinesias. These side effects have been linked to the blockade of dopamine receptors in the striatum. 5 Clozapine (1), an "atypical" antipsychotic, is relatively free of extrapyramidal side effects, but causes tachycardia (25%), sialorrhea (30%), dizziness (20%), drowsiness and sedation (40%), and agranulocytosis (1-3%). Many of these side effects can be attributed to clozapine's high affinity for a number of central nervous system (CNS) receptors. 6 At the same time, clozapine's affinity for the D 4 receptor may play a part in its atypical nature.