Omega-3 fatty acid supplementation for the treatment of children with attention-deficit/hyperactivity disorder symptomatology: systematic review and meta-analysis

Abstract

Objective: Several studies have demonstrated differences in omega-3 fatty acid composition in plasma and in erythrocyte membranes in patients with attention-deficit/hyperactivity disorder (ADHD) compared with unaffected controls. Omega-3 fatty acids have anti-inflammatory properties and can alter central nervous system cell membrane fluidity and phospholipid composition. Cell membrane fluidity can alter serotonin and dopamine neurotransmission. The goal of this meta-analysis was to examine the efficacy of omega-3 fatty acid supplementation in children with ADHD.

Method: PubMed was searched for randomized placebo-controlled trials examining omega-3 fatty acid supplementation in children with ADHD symptomatology. The primary outcome measurement was standardized mean difference in rating scales of ADHD severity. Secondary analyses were conducted to determine the effects of dosing of different omega-3 fatty acids in supplements.

Results: Ten trials involving 699 children were included in this meta-analysis. Omega-3 fatty acid supplementation demonstrated a small but significant effect in improving ADHD symptoms. Eicosapentaenoic acid dose within supplements was significantly correlated with supplement efficacy. No evidence of publication bias or heterogeneity between trials was found.

Conclusion: Omega-3 fatty acid supplementation, particularly with higher doses of eicosapentaenoic acid, was modestly effective in the treatment of ADHD. The relative efficacy of omega-3 fatty acid supplementation was modest compared with currently available pharmacotherapies for ADHD such as psychostimulants, atomoxetine, or α(2) agonists. However, given its relatively benign side-effect profile and evidence of modest efficacy, it may be reasonable to use omega-3 fatty supplementation to augment traditional pharmacologic interventions or for families who decline other psychopharmacologic options.

Copyright © 2011 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Flow Chart Depicting Selection of Studies

Note: ADHD = attention-deficit/hyperactivity disorder.

Figure 2. Omega-3 Fatty Acid Supplementation for Attention-Deficit Hyperactivity Disorder (ADHD)

Note: Forest plot depicting efficacy of omega-3 fatty acid supplementation compared to placebo in the treatment of children with ADHD symptoms. Ten studies involving 699 participants contributed to this analysis. There was a significant benefit of omega-3 supplementation compared to placebo and no evidence of heterogeneity or publication bias. CI = confidence interval.

Figure 3. Eicosapentaenoic acid dose and Efficacy of Omega-3 Fatty Acid Supplementation for Attention-Deficit Hyperactivity Disorder (ADHD)

Note: Scatterplot of measured efficacy of omega-3 fatty acid supplementation in trials as a function of Eicosapentaenoic acid (EPA) dose utilized. Trials were weighted (size of circles) using the generic inverse variance method. Higher doses of EPA within essential fatty acids supplements was significantly associated with increased efficacy in treating ADHD symptoms (β=0.36 (95% CI: 0.01–0.72), t=2.34, p=0.04, R2=0.38). Two trials, Johnson 2008 (effect size=0.35, EPA dose=558mg weight=11.1%) and Richardson 2005 (effect size=0.36, EPA dose=558mg weight=17.3%) had overlapping point estimates on this figure. CI = confidence interval.