In addition, a study has shown the decrease in cytokine levels such as IL-6 and CRP, after 8-week omega-3 supplementation, in children with ADHD was correlated with significant improvement in clinical symptoms [64], although our own study did not replicate these findings, and pointed to the need of dividing ADHD children in subgroups based on their biomarker profile [65]. This evidence concerns the gene IL6 and attention deficit-hyperactivity disorder.