Expected Incidence of Tardive Dyskinesia Associated With Atypical Antipsychotics

Given the problematic nature of tardive dyskinesia in persons taking conventional antipsychotics,evaluation of newer atypical antipsychotic agents should include a systematic assessment of tardive dyskinesialiability. Results of a prospective double-blind, randomized study of schizophrenic patients whoparticipated in 3 preclinical olanzapine studies and were treated with 5 to 20 mg/day of olanzapine(N = 1192) or haloperidol (N = 522) recently indicated a significantly lower risk of development of tardivedyskinesia with olanzapine treatment than haloperidol treatment. This article discusses the knowneffects of atypical antipsychotic medications on tardive dyskinesia movements (both withdrawal and persistent)and the incidence rate of tardive dyskinesia among schizophrenic patients undergoing long-termtreatment with olanzapine or haloperidol.