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Brain iron concentrations in the pathophysiology of children with attention deficit/hyperactivity disorder: a systematic review

Research output: Contribution to journalArticle

Alexia Degremont, Rishika Jain, Elena Philippou, Gladys Oluyemisi Latunde-Dada

Original languageEnglish
JournalNutrition Reviews
Accepted/In press26 May 2020

King's Authors


Context: Attention deficit/hyperactivity disorder (ADHD) is a neurological disorder associated with iron dysregulation in children. While previous focus was on examining systemic iron status, brain iron content may be a more reliable biomarker of the disorder.

Objective: The present systematic review aimed to examine whether children with ADHD have lower serum as well as brain iron concentration, compared to healthy controls.

Data sources: A systematic literature search was conducted in Medline via PubMed, the Cochrane Library, Web of Science, Embase and Ovid for papers between 2000 to June 7th 2019.

Data extraction: Studies were included if the mean difference of iron concentration, measured as serum iron, serum ferritin or brain iron, between children with ADHD and healthy controls was an outcome measure.

Data analysis: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Risks of bias within and between studies were assessed using the quality assessment tools of the National Institutes of Health.

Out of 599 records screened, 20 case-control studies met the inclusion criteria. In 10 out of 18 studies assessing serum ferritin and 2 out of 10 studies assessing serum iron, a significant difference between children with ADHD and healthy controls was observed, respectively. Results of systemic iron levels were inconsistent. In 3 studies where brain iron was assessed, a statistically significantly lower thalamic iron concentration was found in children with ADHD compared to healthy controls.

Conclusion: The evidence, though limited, reveals that brain iron rather than systemic iron levels may be more associated with the pathophysiology of ADHD in children. Larger longitudinal magnetic resonance imaging studies are needed in order to examine any correlations of iron deficiency in specific brain regions and symptoms of ADHD.

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