Iron Deficiency in Attention- Deficit Hyperactivity Disorder, Autism Spectrum Disorder, Internalizing and Externalizing Disorders, and Movement Disorders

Iron is essential for brain development and function. Children, particularly females and those from minority backgrounds, are among the most vulnerable populations to developing ID. Before anemia becomes manifest, low body iron stores may alter brain structure and function, causing a variety of neuropsychiatric symptoms. In fact, ID is frequently found in patients with ADHD, where it is associated with more severe symp-toms and possibly poorer response to psychostimulants. ID has also been associated with the severity of internalizing symptoms, ASD, movement disorders, and sleep dis-orders. These findings are important to bear in mind as they are telling of a potentially reversible risk factor for psychopathology. Treating ID can have important clinical ramifications, with regard to reducing the severity of certain psychiatric conditions and/or optimizing treatment efficacy and tolerability. However, iron supplementation may be associated with certain risks, including dysbiosis and increased infection risk.108 Therefore, research is urgently needed to determine what threshold may be optimal for preventing brain iron insuffi-ciency or depletion, rather than merely preventing anemia. To that end, advances in neuroimaging will help shed light on factors that modulate brain iron content and its impact on brain structure and function, in children and adolescents with and without psychopathology. The public health impact of such work can be substantial. For a summary of quality of research and benefits based on randomized controlled trial, please see Table 4.