Food and Behaviour Research

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A randomized, double-blind, placebo-controlled trial of docosahexaenoic acid supplementation in children with attention-deficit/hyperactivity disorder.

Voigt RG, Llorente AM, Jensen CL, Fraley JK, Berretta MC, Heird WC. (2001) J Pediatr.  139(2) 189-96. 

Web URL: View this and related research articles via PubMed here

Abstract:

OBJECTIVE:

To determine whether docosahexaenoic acid (DHA) supplementation for 4 months decreases the symptoms of attention-deficit/hyperactivity disorder (ADHD).

STUDY DESIGN:

Sixty-three 6- to-12-year-old children with ADHD, all receiving effective maintenance therapy with stimulant medication, were assigned randomly, in a double-blind fashion, to receive DHA supplementation (345 mg/d) or placebo for 4 months. Outcome variables included plasma phospholipid fatty acid patterns, scores on laboratory measures of inattention and impulsivity (Test of Variables of Attention, Children's Color Trails test) while not taking stimulant medication, and scores on parental behavioral rating scales (Child Behavior Checklist, Conners' Rating Scale). Differences between groups after 4 months of DHA supplementation or placebo administration were determined by analysis of variance, controlling for age, baseline value of each outcome variable, ethnicity, and ADHD subtype.

RESULTS:

Plasma phospholipid DHA content of the DHA-supplemented group was 2.6-fold higher at the end of the study than that of the placebo group (4.85 +/- 1.35 vs 1.86 +/- 0.87 mol % of total fatty acids; P <.001). Despite this, there was no statistically significant improvement in any objective or subjective measure of ADHD symptoms.

CONCLUSION: A 4-month period of DHA supplementation (345 mg/d) does not decrease symptoms of ADHD.

FAB RESEARCH COMMENT:

This clinical trial found no benefits of supplementation with omega-3 DHA over placebo, as an adjunct to stimulant medication, in children clinically diagnosed with ADHD.

Previous studies have reported low blood levels of DHA (and other long-chain omega-3, as well as omega-6) fatty acids in children with ADHD compared with matched controls, and other evidence points to possible abnormalities of fatty acid metabolism in this and related conditions, including dyslexia, dyspraxia and autism.

All of these conditions show a high degree of overlap with each other, and also with other psychiatric disorders such as depression, bipolar disorder and schizophrenia, in which omega-3 deficiencies have also been implicated.

It may therefore be relevant that this study rigorously excluded children whose ADHD was comorbid with other psychiatric disorders, 

The use of pure DHA (from an algal source) rather than fish oils - which contain both EPA and DHA - might also be important - as EPA alone has already shown benefits in reducing symptoms of both depression ad schizophrenia, while pilot studes found no benefits of DHA in these conditions.

Both populations, and treatment formulations and dosages, require further research in this area.