ADHD in children is characterized by inattention, short attention span, excessive activity and emotional impulsivity. These children have normal or basically normal intelligence, but have learning, behavioral and emotional deficits, and generally have poor academic performance. There is no specific nutrient deficiency in the development of this disease. It is possible that some patients have a nutrient deficiency or insufficiency, but this is not specific. The etiology and pathogenesis of the disease is unknown and is currently thought to be the result of a multifactorial interaction of genetic and environmental factors. There is some familial aggregation, and magnetic resonance imaging reveals abnormal frontal lobe development, reduced volume of the corpus callosum and caudate nucleus, hypofunction of central nervous system dopamine and norepinephrine neurotransmitters, and hyperfunction of 5-HT. Family breakdown, inappropriate parenting style, poor parental personality, depression or dissociative disorder in the mother, antisocial behavior or substance dependence in the father, family financial difficulties, crowded housing, childhood separation from parents, abuse, and inappropriate schooling methods may be associated with the disorder.