Iron may help treat ADHD

Dec. 6, 2004 -- Iron deficiency may contribute to the physiopathology of attention deficit-hyperactivity disorder (ADHD) in children, according to the results of a controlled group comparison study published in the December issue of the Archives of Pediatric & Adolescent Medicine. Iron supplementation may benefit this population.

"Iron deficiency has been previously considered a potent cause of poor cognitive impairment, learning disability, and psychomotor instability," writes Eric Konofal, MD, PhD, from Robert Debré Hospital in Paris, France, and colleagues. "[I]ron deficiency could lead to ADHD symptoms in relationship with central dopaminergic dysfunction."

In the study, the investigators found that serum ferritin levels were significantly lower in children with ADHD (n = 53; mean age, 9.2 ± 2.2 years) compared with age- and sex-matched control subjects (n = 27; mean age, 9.5 ± 2.8 years) with mild reading disabilities (serum ferritin levels, 23 ± 13 ng/mL vs 44 ± 22 ng/mL, respectively; P < .001).
Serum ferritin levels were also abnormally low (< 30 ng/mL) in a significantly greater proportion of children with ADHD compared with control subjects (84% vs 18%; P < .001).

In children with ADHD, low serum ferritin levels were correlated with more severe general symptom scores on the Conners' Parent Rating Scale (Pearson correlation coefficient [ r] = - 0.34; P < .02) as well as greater cognitive deficits ( r = - 0.38; P < .01). A trend toward a correlation with greater hyperactivity was also observed but did not achieve significance ( r = - 0.57; P = .055).

"Only the cognitive subscore correlated significantly with low ferritin levels," the authors note. "This correlation suggests that the iron-deficient children are mainly inattentive and distractable and suffer from learning disabilities, a finding consistent with the role of iron deficiency in cognitive defects and mental retardation.
"[I]ron supplementation could be considered a first-line treatment for children with ADHD and iron deficiency," the authors conclude, adding that such therapy may improve central dopaminergic activity and decrease the need for psychostimulants.

The authors report no pertinent financial conflicts of interest.
Arch Pediatr Adolesc Med. 2004;158:1113-1115
Reviewed by Gary D. Vogin, MD