Reduced Symptoms of Inattention after Dietary Omega-3 Fatty Acid Supplementation in Boys with and without Attention Deficit/Hyperactivity Disorder

Abstract

Attention deficit/hyperactivity disorder (ADHD) is one of the most common child psychiatric disorders, and is often treated with stimulant medication. Nonpharmacological treatments include dietary supplementation with omega-3 fatty acids, although their effectiveness remains to be shown conclusively. In this study, we investigated the effects of dietary omega-3 fatty acid supplementation on ADHD symptoms and cognitive control in young boys with and without ADHD. A total of 40 boys with ADHD, aged 8-14 years, and 39 matched, typically developing controls participated in a 16-week double-blind randomized placebo-controlled trial. Participants consumed 10 g of margarine daily, enriched with either 650 mg of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) each or placebo. Baseline and follow-up assessments addressed ADHD symptoms, fMRI of cognitive control, urine homovanillic acid, and cheek cell phospholipid sampling. EPA/DHA supplementation improved parent-rated attention in both children with ADHD and typically developing children. Phospholipid DHA level at follow-up was higher for children receiving EPA/DHA supplements than placebo. There was no effect of EPA/DHA supplementation on cognitive control or on fMRI measures of brain activity. This study shows that dietary supplementation with omega-3 fatty acids reduces symptoms of ADHD, both for individuals with ADHD and typically developing children. This effect does not appear to be mediated by cognitive control systems in the brain, as no effect of supplementation was found here. Nonetheless, this study offers support that omega-3 supplementation may be an effective augmentation for pharmacological treatments of ADHD (NCT01554462: The Effects of EPA/DHA Supplementation on Cognitive Control in Children with ADHD; http://clinicaltrials.gov/show/NCT01554462).

Figure 1

Trial design. Schematic overview of the design of this double-blind randomized placebo-controlled trial, including all measures that were collected and the number of participants that were included at baseline. After 1, 2, and 3 months, interim visits took place during which compliance and behavior were measured. ADHD, attention deficit/hyperactivity disorder; CBCL, Child Behavior Checklist; DLCQ, Diet and Lifestyle Change Questionnaire; EFAQ, Essential Fatty Acids Questionnaire; SWAN, Strengths and Weaknesses of ADHD symptoms and Normal behavior scale; RG, reference group of typically developing children.

Figure 2

Main effect of omega-3 PUFA supplementation. (a) The mean difference between baseline and follow-up CBCL attention problems in both diagnostic groups, with main effects of diagnosis and the intervention. (b) The mean difference between baseline and follow-up square-root transformed %DHA levels as collected from cheek cell samples, with similar main effects. The asterisks denote significance at p<0.01. ADHD, attention deficit/hyperactivity disorder; CBCL, Child Behavior Checklist; DHA, docosahexaenoic acid; RG, reference group of typically developing children.

Figure 3

The relation between omega-3 fatty acids and attention problems in ADHD, at baseline and at follow-up. (a) Correlation at baseline between square-root transformed %DHA and CBCL attention problems in children with ADHD (r=−0.47). (b) The same correlation at follow-up (r=−0.48). There was no correlation between %DHA and CBCL attention problems in typically developing children. ADHD, attention deficit/hyperactivity disorder; CBCL, Child Behavior Checklist; DHA, docosahexaenoic acid.