Reduction in perseverative errors with adjunctive ethyl-eicosapentaenoic acid in patients with schizophrenia: Preliminary study

IntroductionPatients with schizophrenia have significant cognitive deficits, generally resistant to conventional treatment. This preliminary study examined the effects of ethyl-eicosapentanoate (EPA) on an executive function in early course patients.Patients and methodsPatients with schizophrenia were given, after an informed consent, 2 g of an EPA daily for 24 weeks, in an open-label study. The Wisconsin Card Sort Test (WCST) was administered at baseline, weeks 4, 12 and 24.ResultsThe 27 patients, with a mean duration of illness of 4.2 years, were all receiving atypical antipsychotics; treatment remained unchanged for the study. Perseverative errors – the key measure derived from WCST – were significantly reduced from the baseline mean of 28.2 to 18.4 errors at week 24. Positive symptoms also improved significantly. There were no correlations between EPA levels and any clinical or other neuropsychological measures.ConclusionThese findings suggest that an EPA has procognitive effects for patients with schizophrenia, but controlled trials are required.