A double-blind placebo-controlled study of vitamin E treatment of tardive dyskinesia.

BACKGROUND

This study was designed to determine if vitamin E is effective in reducing the severity of abnormal movements in patients with tardive dyskinesia (TD).

METHOD

Thirty-five patients completed a double-blind placebo-controlled parallel-group study of vitamin E. Seventeen of the patients were randomly assigned to receive 800 IU b.i.d. of vitamin E and 18 were assigned to placebo for 2 months. Twenty-nine patients had a diagnosis of schizophrenia and 6 of mood disorder. Patients were assessed using modified versions of the Abnormal Involuntary Movement Scale (mAIMS), Simpson-Angus Scale for extrapyramidal side effects, and Brief Psychiatric Rating Scale. Additionally, a subgroup of 23 patients were assessed using instrumental measurements of dyskinesia.

RESULTS

There was a significant reduction of dyskinesia in the vitamin E group, but not the placebo group, on both the mAIMS and the instrumental assessments. The overall reduction in mAIMS in the active group was 24%, with 5 (29%) of 17 patients demonstrating greater than 33% reduction in score. There was a greater reduction in mean mAIMS score (35%) with vitamin E in the subgroup of patients with TD for 5 years or less compared with the reduction (11%) in patients with TD for greater than 5 years. No change was observed in parkinsonism. In the patients with schizophrenia, there was a reduction in positive symptoms after vitamin E.

CONCLUSION

Vitamin E appears to be effective in reducing the severity of TD, especially in patients who have had TD for 5 years or less.