IronDeficiency Across Neurodevelopmental Disorders: Comparative Insights from ADHD and Autism Spectrum Disorder

Background: Iron plays a crucial role in neurotransmitter synthesis, myelination, and neuronal metabolism. Iron deficiency has been associated with a variety of neurodevelopmental disorders, particularly attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). However, the prevalence, clinical impact, and treatment implications differ between these conditions. Objective: To synthesize current evidence on the prevalence, neurobehavioral consequences, and therapeutic implications of iron deficiency in ADHD and ASD, highlighting convergences and disorder-specific findings. Results: In ADHD, studies using serum ferritin and related peripheral markers show inconsistent associations with core symptom severity, with reported ferritin thresholds for deficiency ranging widely. While some studies suggest links between low ferritin and hyperactivity, inattention, or stimulant response, others report null findings. In contrast, emerging neuroimaging evidence consistently demonstrates reduced brain iron in dopaminergic regions in children. In ASD, the strongest link is between low ferritin and sleep-related motor disturbances, and iron supplementation may improve sleep and motor symptoms. Conclusions: Screening for iron status and targeted supplementation may improve sleep and behavioral outcomes in ADHD and ASD, meriting integration into clinical practice and further randomized controlled trials.