Objective: To evaluate the efficacy of an Omega-3/Omega-6 fatty acid supplement in preschool children at risk for ADHD. Method: Forty preschool children with elevated levels of ADHD symptoms were randomly assigned to either a verum or a placebo group. Children in the verum group received a 4-month treatment with Omega-3/Omega-6 fatty acids. Outcome measures comprised parent- and teacher-rated ADHD symptoms, which were the primary outcome variables, internalizing and externalizing problems, and intellectual abilities. Results: Intention-to-treat analyses of covariance, controlling for age and baseline data, revealed effects on parent- and teacher-rated ADHD symptoms (primary outcomes; parent ratings: F = 4.51, df = 1, p = .04, d = 0.63; teacher ratings: F = 4.67, df = 1, p = .04, d = 0.70), parent-rated internalizing symptoms (F = 8.47, df = 1, p < .01, d = 0.63), and parent- and teacher-rated externalizing symptoms (parent ratings: F = 4.58, df = 1, p = .04, d = 0.54; teacher ratings: F = 5.99, df = 1, p = .02, d = 0.79). Analyses involving only cases with available data yielded significant moderate effects on teacher-rated inattention symptoms (F = 4.60, df = 1, p = .04, d = 0.79) and parent-rated internalizing problems (F = 6.04, df = 1, p = .02, d = 0.57). Conclusion: The intention-to-treat analyses provide some evidence for positive effects of Omega-3/Omega-6 fatty acids. However, the results require replication in larger samples to allow for firm conclusions for practice.
Keywords: Omega-3/Omega-6 fatty acids; attention-deficit/hyperactivity disorder; placebo-controlled randomized trial; polyunsaturated fatty acids; preschool children.