Effects of omega-3 polyunsaturated fatty acid supplementation on cognitive functioning in youth at ultra-high risk for psychosis: secondary analysis of the NEURAPRO randomised controlled trial.

BACKGROUND: Cognitive impairments are well-established features of psychotic disorders and are present when individuals are at ultra-high risk for psychosis. However, few interventions target cognitive functioning in this population. AIMS: To investigate whether omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation improves cognitive functioning among individuals at ultra-high risk for psychosis. METHOD: Data (N = 225) from an international, multi-site, randomised controlled trial (NEURAPRO) were analysed. Participants were given omega-3 supplementation (eicosapentaenoic acid and docosahexaenoic acid) or placebo over 6 months. Cognitive functioning was assessed with the Brief Assessment of Cognition in Schizophrenia (BACS). Mixed two-way analyses of variance were computed to compare the change in cognitive performance between omega-3 supplementation and placebo over 6 months. An additional biomarker analysis explored whether change in erythrocyte n-3 PUFA levels predicted change in cognitive performance. RESULTS: The placebo group showed a modest greater improvement over time than the omega-3 supplementation group for motor speed (ηp2 = 0.09) and BACS composite score (ηp2 = 0.21). After repeating the analyses without individuals who transitioned, motor speed was no longer significant (ηp2 = 0.02), but the composite score remained significant (ηp2 = 0.02). Change in erythrocyte n-3 PUFA levels did not predict change in cognitive performance over 6 months. CONCLUSIONS: We found no evidence to support the use of omega-3 supplementation to improve cognitive functioning in ultra-high risk individuals. The biomarker analysis suggests that this finding is unlikely to be attributed to poor adherence or consumption of non-trial n-3 PUFAs.

Omega-3 fatty acids and neurocognitive ability in young people at ultra-high risk for psychosis.

BACKGROUND: Neurocognitive impairments are core early features of psychosis and are observed in those at ultra-high risk (UHR) for psychosis. The aim of the present study was to explore whether neurocognition is associated with polyunsaturated fatty acids (PUFAs), as has been observed in other clinical populations. METHOD: Erythrocyte levels of total omega-3-and omega-6 PUFAs the omega-3/omega-6 ratio, were measured in 265 UHR individuals. Six domains of neurocognition as well a Composite Score, were assessed using the Brief Assessment of Cognition in Schizophrenia. Pearson's correlations were used to assess the relationship between PUFAs and neurocognition. All analyses were controlled for tobacco smoking. RESULTS: Verbal Fluency correlated positively with eicosapentaenoic acid (P = .024) and alpha-linolenic acid (P = .01), and negatively with docosahexanoic acid (P = .007) and Working Memory positively correlated with omega-3/omega-6 ratio (P = .007). CONCLUSIONS: The current results provide support for a relationship between Verbal Fluency and omega-3 PUFAs in UHR. Further investigation is required to elucidate whether these biomarkers are useful as risk markers or in understanding the biological underpinning of neurocognitive impairment in this population.