title: Prevalence of and risk factors for tardive dyskinesia in a Xhosa population in the Eastern Cape of South Africa.
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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Rhodes University, Grahamstown, South Africa. betty.patterson@ndsu.nodak.edu
authors.forename: Betty D
authors.initials: BD
authors.lastname: Patterson
authors.forename: Dave
authors.initials: D
authors.lastname: Swingler
authors.forename: Sandi
authors.initials: S
authors.lastname: Willows
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D003692:Delayed-Action Preparations; D004409:Dyskinesia, Drug-Induced / Q000453:epidemiology / Q000208:ethnology* / Q000517:prevention & control; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D015994:Incidence; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000706:statistics & numerical data; D044382:Population Groups; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013019:South Africa / Q000453:epidemiology
chemical_list: D000975:Antioxidants; D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations