title: The effects of eicosapentaenoic acid in tardive dyskinesia: a randomized, placebo-controlled trial.
abstract: OBJECTIVE
  Worldwide, conventional antipsychotic medication continues to be used extensively, and tardive dyskinesia (TD) remains a serious complication. The primary objective of the present study was to compare the efficacy of EPA versus placebo in reducing symptoms of TD.
  
  
  METHODS
  This was a 12-week, double-blinded, randomized study of ethyl-EPA 2g/day versus placebo as supplemental medication, in patients with schizophrenia or schizoaffective disorder, with established TD.
  
  
  RESULTS
  Eighty-four subjects were randomized, of whom 77 were included in the analysis. Both the EPA and placebo groups displayed significant baseline to endpoint improvements in Extrapyramidal Symptom Rating Scale dyskinesia scores, but there were no significant between-group differences (p=0.4). Response rates (>or=30% improvement in TD symptoms) also did not differ significantly between EPA-treated subjects (45%) and placebo-treated subjects (32%) (p=0.6). However, a post-hoc linear mixed model repeated measures analysis of variance indicated an effect for treatment group and duration of TD. The EPA-treated patients had significantly greater mean reductions in dyskinesia scores initially, although this was not sustained beyond 6 weeks.
  
  
  CONCLUSIONS
  This trial failed to demonstrate an anti-dyskinetic effect for ethyl-EPA 2g/day on the primary efficacy measure. However, a modest and transient benefit is suggested in patients with more recent onset of TD. The lack of clear-cut efficacy could be explained on the basis of the dose of EPA being too low, the study being underpowered, TD being too chronic in the majority of cases, differences in dietary fatty acid intake, or that EPA lacks an anti-dyskinetic action.
authors.affiliation: Department of Psychiatry, Faculty of Health Sciences, University of Stellenbosch, PO Box 19063, Tygerberg 7505, Cape Town, South Africa. rae@sun.ac.za
authors.forename: Robin
authors.initials: R
authors.lastname: Emsley
authors.forename: Dana J H
authors.initials: DJ
authors.lastname: Niehaus
authors.forename: Liezl
authors.initials: L
authors.lastname: Koen
authors.forename: Piet P
authors.initials: PP
authors.lastname: Oosthuizen
authors.forename: H Jadri
authors.initials: HJ
authors.lastname: Turner
authors.forename: Paul
authors.initials: P
authors.lastname: Carey
authors.forename: Susan Janse
authors.initials: SJ
authors.lastname: van Rensburg
authors.forename: J Stefan
authors.initials: JS
authors.lastname: Maritz
authors.forename: Harald
authors.initials: H
authors.lastname: Murck
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects; D001480:Basal Ganglia Diseases / Q000139:chemically induced / Q000188:drug therapy; D003024:Clozapine / Q000009:adverse effects; D004311:Double-Blind Method; D004409:Dyskinesia, Drug-Induced / Q000188:drug therapy* / Q000209:etiology; D015118:Eicosapentaenoic Acid / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000188:drug therapy; D012559:Schizophrenia / Q000188:drug therapy
chemical_list: D014150:Antipsychotic Agents; D015118:Eicosapentaenoic Acid; D003024:Clozapine