While limited evidence suggests that omega-3 supplementation may reduce antisocial behaviour in children, studies have not reported on post-treatment follow-up and most treatment periods have been of short duration. This study tests the hypothesis that omega-3 supplementation over 6 months will reduce behaviour problems in children both at the end of treatment and at 6 months post treatment.
In this randomised, double-blind, placebo-controlled, stratified, parallel-group trial, a community sample of 8-16 year old children were randomised into a treatment group (N = 100) and a placebo-control group (N = 100). The supplementation consisted of a fruit drink containing 1 g/day of omega-3 or a placebo consisting of the same fruit drink without omega-3. Participants, caregivers, and research assistants were blinded to group assignment. The primary outcome measures of externalising and internalising behaviour problems were reported by both caregivers and their children in a laboratory setting at 0 months (baseline), 6 months (end of treatment) and 12 months (6 months post treatment), together with the secondary outcome measures of parental antisocial behaviour. Data were analysed on an intention-to-treat basis including all participants.
Significant group × time interactions were observed with the treatment group showing long-term improvements in child behaviour problems. The average post-treatment effect size was d = -.59. Effects were documented for parent reports, but with the exception of proactive and reactive aggression, child-report data were nonsignificant. Parents whose children took omega-3 showed significant post-treatment reductions in their own antisocial and aggressive behaviour. This improvement in caregiver behaviour partly mediated the improvements observed in child behaviour.
Findings provide initial evidence that omega-3 supplementation can produce sustained reductions in externalising and internalising behaviour problems. Results are the first to report improvements in caregiver behaviour, and to establish this improvement as a part-mechanism for the efficacy of omega-3.
J Child Psychol Psychiatry. 2014 Aug 22. http://www.ncbi.nlm.nih.gov/pubmed/25146492