A placebo-controlled trial of omega-3 fatty acid (ethyl eicosapentaenoic acid) supplementation for residual symptoms and cognitive impairment in schizophrenia

objective: This study determined if augmentation of neuroleptics with 3 g/day of ethyl eicosapentaenoic acid (EPA) improves symptoms and cognition in patients with schizophrenia or schizoaffective disorder. Method: Eighty-seven patients meeting criteria for schizophrenia or schizoaffective disorder who had residual symptoms despite neuroleptic treatment were randomly assigned to receive either 3 g/day of ethyl EPA (N=43) or placebo (N=44) in a 16-week, double-blind supplementation trial. Assessments were performed at baseline and at weeks 1, 2, 4, 8, 12, and 16; a cognitive battery was administered at baseline and at week 16. Results: No differences were found between groups in positive or negative symptoms, mood, cognition, or global impression ratings. Results were similar for the intention-to-treat (N=87) and completer (N=75) groups. Conclusions: For schizophrenia patients treated with 3 g/day of ethyl EPA, improvement in residual symptoms and cognitive impairment was no greater than for schizophrenia patients treated with placebo.