To determine whether supplementation with the long-chain omega-3 polyunsaturated fatty acids eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) affects behavioral symptoms and cognitive impairments in children 6-12 years of age diagnosed with attention-deficit/hyperactivity disorder (ADHD).

The randomized, double-blind placebo-controlled 16 weeks trial was conducted with 95 children diagnosed with ADHD according to DSM-IV criteria. Behavior was assessed by parents, teachers and investigators using standardized rating scales and questionnaires. Further outcome variables were working memory, speed of information processing and various measures of attention. For a subgroup of 81 participants, erythrocyte membrane fatty acid composition was analyzed before and after the intervention.

Supplementation with the omega-3 fatty acid mix increased EPA and DHA concentrations in erythrocyte membranes and improved working memory function, but had no effect on other cognitive measures and parent- and teacher-rated behavior in the study population. Improved working memory correlated significantly with increased EPA, DHA and decreased AA (arachidonic acid).