Effect of docosahexaenoic acid-containing food administration on symptoms of attention-deficit/hyperactivity disorder - a placebo-controlled double-blind study

Objectives: To investigate whether docosahexaenoic acid (DHA) supplementation was able to ameliorate attention-deficit/hyperactivity disorder(AD/HD) symptoms in AD/HD children. Design and subjects: A placebo-controlled double-blind study with 40 AD/HD (including eight AD/HD-suspected) children of 6-12 y of age who were mostly without medication. Subjects of a DHA group (n = 20) took active foods containing fish oil (fermented soybean milk, bread rolls and steamed bread; 3.6 g DHA/week from these foods) for 2 months, whereas those of a control group (n = 20) took indistinguishable control foods without fish oil. The following items were measured at the start and end of the study: (1) attention deficit, hyperactivity and impulsivity (AD/HD-related symptoms according to DSM-IV criteria); (2) aggression assessed by both parents and teachers; (3) visual perception ( finding symbols out of a table); (4) visual and auditory short-term memory; (5) development of visual-motor integration; (6) continuous performance; (7) impatience. Results: Changes in tests 1, 2, 3, 5 and 7 over time did not significantly differ between the two groups. However, visual short-term memory and errors of commission (continuous performance) significantly improved in the control group compared with the changes over time in the DHA group (P = 0.02 and 0.001, respectively). Recalculation without AD/HD-suspected subjects (n = 4 each group) showed similar P-values with regard to both measures. Conclusion: DHA supplementation did not improve AD/HD-related symptoms. Treatment of ADHD with fatty acids deserves further investigation, but careful attention should be paid as to which fatty acid(s) is used.