Attention Deficit Hyperactivity Disorder appears in children less than 7 years old. However, it is a chronic disease that begins in childhood and continues until adulthood. More than millions of children around the world become victims of this disorder due to various reasons. However, iron deficiency is the most significant cause of ADHD, say French scientists. According to the kids who have low iron stores have more severe symptoms of Attention Deficit Hyperactivity Disorder.