The effects of eicosapentaenoic acid in tardive dyskinesia: a randomized, placebo-controlled trial.
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.
Emsley
Robin
R
Department of Psychiatry, Faculty of Health Sciences, University of Stellenbosch, PO Box 19063, Tygerberg 7505, Cape Town, South Africa. rae@sun.ac.za
Niehaus
Dana J H
DJ
Koen
Liezl
L
Oosthuizen
Piet P
PP
Turner
H Jadri
HJ
Carey
Paul
P
van Rensburg
Susan Janse
SJ
Maritz
J Stefan
JS
Murck
Harald
H
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
D014150:Antipsychotic Agents; D015118:Eicosapentaenoic Acid; D003024:Clozapine