Method: Subjects with pre-existing neuroleptic-induced tardive dyskinesia were chosen from Taoyuan psychiatric center. Patients recruited would be treated with aripiprazole for cross-titration with previous antipsychotics in 8 weeks. We use AIMS, SAS, & BAS to assess the severity of TF and EPS. We record subjects' age, sex, and other factors which have influence at the treatment response. Subjects are assessed every two weeks in the first month and then monthly until six months.