Risperidone for severe tardive dyskinesia: A 12-week randomized, double-blind, placebo-controlled study

Background. Risperidone has been reported to alleviate the severity of tardive dyskinesia, but without placebo control, the possibility of spontaneous tardive dyskinesia remission after discontinuing original conventional antipsychotics cannot be excluded. This 12-week randomized, double-blind, placebo-controlled study investigated the effect of risperidone on severe tardive dyskinesia. Method: Forty-nine DSM-IV schizophrenia patients with severe tardive dyskinesia were enrolled in the study. After a 4-week washout period, the subjects were randomly assigned to treatment with either risperidone or placebo. The risperidone dose was started at 2 mg/day and gradually increased to 6 mg/day over 6 weeks; the 6-mg/day dose was maintained for the remaining 6 weeks of the study. The subjects were evaluated every 2 weeks with the Abnormal Involuntary Movement Scale (AIMS) and the Extrapyramidal Symptom Rating Scale. The final mental status was assessed with the Brief Psychiatric Rating Scale. Results: Twenty-two subjects in the risperidone group and 20 subjects in the placebo group completed the study; the mean baseline AIMS total score for all subjects was 15.9 +/- 4.6. At the end of the study, the mean AIMS total score decrease was 1.1 +/- 4.8 in the placebo group and 5.5 +/- 3.8 in the risperidone group (p < .05). Fifteen subjects (68%) in the risperidone group and 6 subjects (30%) in the placebo group were responders (p < .05). The risperidone responders had a mean AIMS total score decrease of 7.5 +/- 2.1. More significant tardive dyskinesia improvement among the risperidone group was noted from the eighth week and was mainly demonstrated in the buccolinguomasticatory a rea rather than in choreoathetoid movement of the extremities (p < .001). Conclusions: Risperidone, 6 mg/day, can improve tardive dyskinesia more significantly than discontinuing antipsychotics in patients with severe tardive dyskinesia, especially in the orofacial areas.