Prevalence of and risk factors for tardive dyskinesia in a Xhosa population in the Eastern Cape of South Africa
Received 2 July 2004; received in revised form 20 October 2004; accepted 26 October 2004.
Abstract
Objective
Despite prolonged use of antipsychotic drug treatment, the prevalence of tardive dyskinesia (TD) in a Xhosa population has not been evaluated. This study was undertaken to assess the prevalence and identify possible factors, including antioxidant intake and smoking history, which may increase or reduce the risk of TD.
Method
One hundred two subjects who had been exposed to typical antipsychotic drugs for at least 6 months and were currently on an antipsychotic were screened for abnormal movements using the Abnormal Involuntary Movement Scale (AIMS) rating scale. Data about current and past antipsychotic therapy, diagnoses, smoking history, and dietary factors were gathered from the patient and from chart view.
Result
Twenty-eight and four-tenths percent of subjects met criteria for tardive dyskinesia. Years of treatment and total cumulative antipsychotic dose were significant predictors of TD. Subjects with higher total consumption of foods containing antioxidants had lower rates of TD, but only consumption of onions was significantly associated with reduced prevalence. TD was less prevalent in smokers, but this difference did not reach statistical significance. Age, sex, and psychiatric diagnosis did not predict presence of TD.
Conclusion
The result of this study indicate that TD in this population is more prevalent than previously believed within this local clinical context. Prolonged treatment and total antipsychotic drug exposure are important risk factors for TD in this population. Further study of the role of concurrent medications and dietary factors is indicated.
Corresponding author. Present address: College of Pharmacy, North Dakota State University Box 5055 Fargo, ND 58105, USA. Tel.: +1 701 231 7603; fax: +1 701 231 7606.
ABSTRACT