May 6, 2005 — Fatty acid supplementation may help children with developmental coordination disorder (DCD), according to the results of a randomized trial published in the May issue of Pediatrics.

"In addition to the core deficits in motor function, this condition is associated commonly with difficulties in learning, behavior, and psychosocial adjustment that persist into adulthood," write Alexandra J. Richardson, DPhil(Oxon), from the University Laboratory of Physiology in Oxford, England, and colleagues from the Oxford-Durham Study. "Mounting evidence suggests that a relative lack of certain polyunsaturated fatty acids may contribute to related neurodevelopmental and psychiatric disorders such as dyslexia and attention deficit/hyperactivity disorder. Given the current lack of effective, evidence-based treatment options for DCD, the use of fatty acid supplements merits investigation."

In this trial, 117 children with DCD were randomized to dietary supplementation with omega-3 and omega-6 fatty acids or placebo for three months in parallel groups, followed by a one-way crossover from placebo to active treatment for an additional three months. Age range was five to 12 years.

Although supplementation had no apparent effect on motor skills, there were significant improvements for active treatment versus placebo in reading, spelling, and behavior for three months of treatment in parallel groups. After crossover, the placebo-active group showed similar changes, and children continuing with active treatment maintained or improved their progress.

No adverse events were reported, and compliance rate was high, suggesting good acceptability of fatty acid supplements.

"Fatty acid supplementation may offer a safe efficacious treatment option for educational and behavioral problems among children with DCD," the authors write. "Additional work is needed to investigate whether our inability to detect any improvement in motor skills reflects the measures used and to assess the durability of treatment effects on behavior and academic progress."

Study limitations include possible lack of generalizability to other age groups and cultures.

"Additional studies are needed to establish both the optimal composition of fatty acid treatments and dose-response relationships," the authors conclude.

Pediatrics. 2005;115:1360-1366

Clinical Context

Study Highlights

• Patients eligible for study participation were between the ages of 5 and 12 years and had a diagnosis of DCD confirmed by criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Subjects were generally otherwise healthy.
• Participants were randomized to receive supplements containing 80% fish oil and 20% evening primrose oil, or matching placebo. The dosing regimen was 2 tablets 3 times a day. The active treatment contained omega-3 fatty acids, omega-6 fatty acids, α-linoleic acid, and vitamin E. Treatment administration was double blinded.
• Children were given the randomized treatment for 3 months, at which point subjects in the placebo group crossed over to active treatment.
• The main study outcomes were motor function, reading and spelling achievement, and teacher-rated ADHD symptoms. These factors were assessed at baseline, 3 months, and 6 months after randomization.
• 117 children underwent randomization. 66.7% of subjects were boys, and the mean age was 105.8 months. The mean full-scale IQ at baseline for the entire cohort was approximately 0.67 SDs below that of other children of the same age.
• 100 children had data available at 6 months.
• At baseline, participants' mean motor scores were at the sixth percentile for age, and these scores improved to the 12th percentile in the both treatment groups at 3 months.
• Both treatment groups were about 1 year below chronologic age in terms of reading and spelling ability at baseline. After 3 months of study therapy, the mean increases in reading ability were 9.5 months in the active treatment group and 3.3 months in the placebo group, a significant difference. The respective increases in spelling ability were 6.6 and 1.2 months. Again, this difference was statistically significant.
• Teacher-reported scores for ADHD had improved in the active treatment group compared with the placebo cohort at 3 months.
• During the crossover phase of the study from 3 to 6 months after randomization, motor scores continued to improve slightly in both groups, with no significant difference related to fatty acid supplementation. However, children changed from placebo to active treatment demonstrated improvements in reading and spelling similar to those seen in the active treatment group from 0 to 3 months. Participants who received active treatment from the outset of the study continued to improve in these outcomes, surpassing the mean values for their chronologic age by 6 months.
• In terms of ADHD symptoms at 6 months, the cohort crossed over to active treatment at 3 months demonstrated a similar improvement when compared with the active treatment group at 0 to 3 months. There was some mild continued improvement in these symptoms in the active treatment group from 3 to 6 months.
• No treatment-related adverse events were reported.

Pearls for Practice

• Children with DCD frequently have concomitant ADHD, autistic disorders, and dyslexia.
• Fatty acid supplementation may improve reading and spelling skills along with symptoms of ADHD in children with DCD. However, such therapy does not seem as effective at improving motor function.

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