Long-term chlorpromazine in rhesus monkeys: production of dyskinesias and changes in social behavior.

The daily administration of chlorpromazine (CPZ) in doses of 8--40 mg/kg over 113 weeks to four rhesus monkeys produced dyskinesias and alterations in social behavior. General activity and social interactions were reduced by CPZ treatment but social aggression was elevated during initial drug administration. These behaviors returned to normal when treatment was discontinued. Dyskinesias appeared during CPZ treatment, and two striking ones, gravel mouth and hand gesture, persisted for 12 weeks after drug withdrawal. These results indicate that dyskinesias which share major features of human tardive dyskinesia can be produced in nonhuman primates by long-term CPZ treatment.