In boys with and without Attention Deficit Hyperactivity Disorder, new research has found that an extra daily dose of Omega-3 fatty acids reduced symptoms of inattention.

The study found that in a small clinical trial involving boys 8 to 14 years old, parents rated their son’s ability to pay attention more highly if the child’s diet was supplemented for 16 weeks with the long-chain fatty acid than if he got a placebo instead.

Conducted in the Netherlands and published in the journal Neuropsychopharmacology, the new research is in line with studies that have found a welter of neuropsychological benefits to Omega-3 supplementation.

In the current study, 40 subjects got an average of 650 mg per day of Docosahexaenoic Acid, or DHA, and 650 mg of Eicosapentaenoic acid, or EPA — two different kinds of Omega-3s — in margarine. Half had been diagnosed with ADHD, and most continued with their stimulant medication while in the trial. The other half were normally developing children whose age, IQ and body mass indices were similar to those in the ADHD group.

The subjects who got margarine without the Omega-3 supplement were equally divided between those with ADHD and those who had no such diagnosis.

The notable finding was that, whether or not they had ADHD, boys who got the Omega-3 supplement were rated by their parents as more attentive.

“Our results indicate that typically developing children also benefit” from Omega-3 supplementation, “showing the importance of Omega-3 polyunsaturated fatty acid intake during development in general,” the authors wrote. They added Omega-3s “may be useful as an augmentation to standard pharmacological therapies” as well.

And they cited recent research that found that children medicated for ADHD symptoms were able to reduce their doses of stimulant medication when they added Omega-3s to their diet.

The fatty acid found plentifully in fish oil has been found to enhance the effectiveness of antidepressant medication in those with depression, to delay first psychotic break in adolescents at high risk of serious mental illness and to boost working memory performance in young, healthy subjects. Other studies have found it useful as an adjunct to stimulant medication in children with ADHD.

But the benefits of Omega-3 supplementation remain uncertain, as other studies have come up short of evidence that it improves mental health and cognitive performance.