Iron Deficiency in Children With Attention-Deficit/Hyperactivity Disorder

Abstract

BACKGROUND: Iron deficiency causes abnormal dopaminergic neurotransmission and may contribute to the physiopathology of attention-deficit/hyperactivity disorder (ADHD). OBJECTIVE: To evaluate iron deficiency in children with ADHD vs iron deficiency in an age- and sex-matched control group. DESIGN: Controlled group comparison study. SETTING: Child and Adolescent Psychopathology Department in European Pediatric Hospital, Paris, France. PATIENTS: Fifty-three children with ADHD aged 4 to 14 years (mean +/- SD, 9.2 +/- 2.2 years) and 27 controls (mean +/- SD, 9.5 +/- 2.8 years). MAIN OUTCOME MEASURES: Serum ferritin levels evaluating iron stores and Conners' Parent Rating Scale scores measuring severity of ADHD symptoms have been obtained. RESULTS: The mean serum ferritin levels were lower in the children with ADHD (mean +/- SD, 23 +/- 13 ng/mL) than in the controls (mean +/- SD, 44 +/- 22 ng/mL; P < .001). Serum ferritin levels were abnormal (<30 ng/mL) in 84% of children with ADHD and 18% of controls (P < .001). In addition, low serum ferritin levels were correlated with more severe general ADHD symptoms measured with Conners' Parent Rating Scale (Pearson correlation coefficient, r = -0.34; P < .02) and greater cognitive deficits (r = -0.38; P < .01). CONCLUSIONS: These results suggest that low iron stores contribute to ADHD and that ADHD children may benefit from iron supplementation.