Treatment of tardive dyskinesia with donepezil: A pilot study

Background: Tardive dyskinesia (TD) remains a significant clinical problem for which there is no uniformly effective treatment. Earlier trials with acetylcholine precursors may have been disappointing because of underlying damage to striatal cholinergic neurons in patients with TD. In contrast, new cholinesterase inhibitors, developed for the treatment of dementia, may improve TD by directly increasing cholinergic synaptic transmission. Method. We conducted an 8-week open-label trial of donepezil in the treatment of TD. Ten patients with schizophrenia or schizoaffective disorder who received stable doses of antipsychotics and met DSM-IV criteria for TD were treated with donepezil, 5 to 10 mg/day, for 6 weeks after a 2-week baseline period. Changes in total Abnormal Involuntary Movement Scale (AIMS) scores measured every 2 weeks were assessed for significance. Patients were also assessed using the Brief Psychiatric Rating Scale, the Mini-Mental State Examination, the Barnes Akathisia Scale, and the Simpson-Angus Scale. Results: Total AIMS scores decreased significantly (p = .0009), with no changes in other measures. Nine patients showed a positive response. Improvement was greatest in orofacial and upper extremity movements. No significant interactions were noted between the total AIMS scores and age (p > .29), duration of TD (p > .38), or duration of antipsychotic treatment (p > .14). Conclusion. Donepezil appeared to be effective in suppressing TD in this pilot study. However, placebo-controlled, double-blind studies are necessary before donepezil can be recommended as a treatment for TD.