A double-blind placebo-controlled randomised trial of omega-3 supplementation in children with moderate ADHD symptoms

Catherine Cornu, Catherine Mercier, Tiphanie Ginhoux, Sandrine Masson, Julie Mouchet, Patrice Nony, Behrouz Kassai, Valérie Laudy, Patrick Berquin, Nathalie Franc, Marie-France Le Heuzey, Hugues Desombre, Olivier Revol

Clinical trials and inconclusive meta-analyses have investigated the effects of omega-3 supplements in children with Attention-Deficit Hyperactivity Disorder (ADHD). We performed a randomised placebo-controlled trial to evaluate the efficacy of omega-3 fatty acids. Children aged 6-15 years with established diagnosis of ADHD were randomised 1:1 to receive either supplements containing docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) or a placebo for 3 months. Psychotropic or omega-3-containing treatments were not authorised during the study. The primary outcome was the change in the Attention-Deficit Hyperactivity Disorder Rating Scale version 4 (ADHD-RS-IV). Other outcomes included safety, lexical level (Alouette test), attention (Test of Attentional Performance for Children-KiTAP), anxiety (48-item Conners Parent Rating Scale-Revised-CPRS-R), and depression (Children's Depression Inventory-CDI). Between 2009 and 2011, 162 children were included in five French child psychiatry centres. The mean age was 9.90 (SD 2.62) years and 78.4% were boys. The inclusion ADHD-RS-IV at was 37.31 (SD 8.40). The total ADHD-RS-IV score reduction was greater in the placebo group than in the DHA-EPA group: -19 (-26, -12)  % and -9.7 (-16.6, -2.9) %, respectively, p = 0.039. The other components of the Conners score had a similar variation but the differences between groups were not significant. Two patients in the DHA-EPA group and none in the placebo group experienced a severe adverse event (hospitalisation for worsening ADHD symptoms). This study did not show any beneficial effect of omega-3 supplement in children with mild ADHD symptoms.