Prevalence of tardive dyskinesia in chronic male inpatients with schizophrenia on long-term clozapine versus typical antipsychotics

This study aimed to examine the prevalence and clinical associated variables of tardive dyskinesia (TD) in a large sample of Chinese inpatients with schizophrenia on long-term treatment with clozapine versus typical antipsychotics. A total of 584 male inpatients with schizophrenia on long-term clozapine (n=341) or typical antipsychotic (n=243) treatment were evaluated using the Abnormal Involuntary Movement Scale (AIMS). The patient's psychopathology was assessed using the Positive and Negative Syndrome Scale. The overall prevalence of TD was 44.5%, with rates of 48.7% in the clozapine group and 38.7% in the typical antipsychotic group (P=0.017). The AIMS score was significantly lower in typical than in clozapine groups (P<0.005). A multiple regression analysis showed that the following variables were significantly associated with the AIMS score: clozapine versus typical medication (P=0.008), Positive and Negative Syndrome Scale negative subscore (P=0.017), and age (P=0.04). There are significant differences in the prevalence and clinical correlates of TD in schizophrenia treated with clozapine versus typical antipsychotics.