Omega-3 fish-oil supplements can improve attention in children with attention deficit hyperactivity disorder (ADHD) just as much as drug treatments, but only in those whose blood levels of omega 3 are low, a study shows.

In the trial, 92 children with ADHD, aged 6-18, were given either high doses of the omega 3 fatty acid EPA (eicosapentaenoic acid) or a placebo for 12 weeks.

Results show that children with the lowest endogenous EPA levels showed improvements in focused attention and vigilance after taking the omega 3 supplements.

The authors, from the UK and Taiwan, said that with methylphenidate (Ritalin), the amount of improvement in attention and vigilance is generally 0.22-0.42.