Omega-3 supplements could improve the attention spans of some children who have been diagnosed with attention deficit hyperactivity disorder, a new study shows—but only if the children are deficient in omega-3 polyunsaturated fatty acids levels, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These researchers previously found a link between omega-3 deficiency and the severity of ADHD symptoms.

"For those children with omega-3 deficiency, fish oil supplements could be a preferable option to standard stimulant treatments," said Carmine Pariante, senior researcher from the Institute of Psychiatry, Psychology & Neuroscience at King's College London. "Our study sets an important precedent for other nutritional interventions, and we can start bringing the benefits of 'personalized psychiatry' to children with ADHD."

Summary: Some children with ADHD who consumed high doses of EPA increased their attention spans more than children who did not receive the supplements. However, the children who received the high doses did not improve as much as the placebo group regarding impulsivity control. Importantly, children with high baseline levels of omega-3s may suffer negative effects of high-dose supplementation.

The study: A 12-week, double-blind, placebo-controlled trial compared the effects of high doses of the omega-3 EPA on cognitive function. Participants were between the ages of 6 and 12, inclusive, and had been diagnosed with ADHD with inattention, hyperactivity or both. Researchers also assessed the participants for oppositional defiant disorder, which manifests in patients often losing their tempers, arguing with adults, defying rules and blaming others, according to the study.

The China Medical University Hospital in Taiwan, which approved the study, referred participants to the study from July 2016 to December 2017.

Participants either had never received medication or had not taken medication during the six months before the study.  

Children with the following disorders or problems were excluded from the study: mental disability, delayed speech or intellectual disability; autism spectrum disorder, conduct disorder, anxiety or major psychiatric disorders; and physical disorders such as thyroid dysfunction or cerebral palsy. Children who already were consuming omega-3 supplements also were excluded.

The hospital recruited 103 children, who were randomly assigned to receive 1.2 grams a day of EPA or a placebo. Of the 103 recruits, 92 completed the study. The mean age of those subjects was 9.5 years old, and 85.9% of them were male.

Blood tests at the beginning and the end of the study showed participants' levels of EPA.

To gauge the results, researchers used  standardized tests to assess participants' focused attention, impulsivity, sustained attention and vigilance at the beginning and the end of the study. With other tests, researchers measured emotional problems as well as working memory and short-term memory.

Lastly, the researchers issued questionnaires to parents, teacher and the participants who were 12 or older to measure the clinical symptoms of ADHD. Those symptoms were evaluated at the start of the study; at weeks one, two, four and eight; and at the end of the study.

The findings: Participants who received EPA supplementation showed greater improvement in focused attention than those in the placebo group. The effect size was .38, meaning that the average improvement in the EPA group was higher than the growth of 38% of the participants in the placebo group. However, the average growth of the placebo group on the impulsivity scale was higher than 43% of the EPA group.

Of the 51 participants who also were diagnosed with oppositional defiant disorder (ODD)—and, therefore, are generally less responsive to medication—the effect size on attention was even greater than for the overall group: The average improvement of participants with ADHD and ODD who received EPA was 66% higher than the average growth of similar participants who received the placebo.

The results in participants with the lowest baseline EPA levels were even more remarkable. Children with the lowest EPA levels who received EPA supplements showed the greatest improvement on an attention assessment. The average improvement in attention among the EPA group was higher than 89% of the average score the place group.

Surprisingly, participants with the highest EPA levels at the beginning of the study who then received EPA supplements improved less than those who received the placebo when assessed for impulsivity. They also improved less than the placebo group in certain symptoms, as reported by parents and teachers.

Study conclusions: The main outcome of this study was finding that EPA supplementation improves focused attention. Children who have low levels of EPA to begin with showed even greater improvement in measures of attention and vigilance.

The analysis shows, though, that EPA supplements may have a negative effect on children who have high baseline EPA levels.

Why the research is interesting: This is the first study to look at how supplementing polyunsaturated fatty acids could affect ADHD symptoms, according to the researchers.

The study also found that children with ADHD and ODD, who usually don't respond well to medication, showed improved attention when they receive EPA supplements.

The data suggest that a combination of EPA and DHA might have a greater effect on ADHD symptoms than EPA alone.

"We support the recent recommendation by a panel of ADHD experts that patients who prefer omega-3 supplements over stimulants should take a combination of DHA and EPA at doses of 750 milligrams or more per day for at least 12 weeks. … We additionally recommend that this strategy should be even more strongly advocated for children with evidence of low endogenous PUFAs levels," the authors wrote.

Authors: Jane Pei-Chen Chang, who is associated with King’s College London, United Kingdom, and China Medical University, Taichung, Taiwan; Kuan-Pin Su, who is associated with King’s College London and China Medical University; Valeria Mondelli, King’s College London; Senthil Kumaran Satyanarayanan, China Medical University Hospital; Hui-Ting Yang, Taipei Medical University, Taipei, Taiwan; and more.

Published: High-dose eicosapentaenoic acid (EPA) improves attention and vigilance in children and adolescents with attention deficit hyperactivity disorder (ADHD) and low endogenous EPA levels, Translational Psychiatry, Nov. 20, 2019.

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