ADHD (attention deficit hyperactivity disorder), or mildly dysfunctional brain syndrome, is a common behavioral problem in childhood. It has two main symptoms, namely attention deficit and hyperactivity, and may be accompanied by impulsive behavior and learning difficulties. It usually begins after the age of 6 years and becomes apparent during the school years and gradually improves with age. Some cases may continue into adulthood. The prevalence of ADHD in children is reported to be between 5% and 10% in foreign countries, and more than 10% in China, with more boys than girls. Attention deficit disorder (also known as attention deficit disorder) Attention deficit disorder is one of the most important manifestations of the disorder. The child’s active attention is diminished and passive attention is increased, manifested by inattention, inability to pay attention in class, and easily distracted by environmental disturbances. The object of attention is frequently shifted from one activity to another. The student is not able to pay attention to homework, and is careless and rash in doing homework. Does not finish what he/she starts, often stops halfway or changes frequently. They procrastinate in doing homework, constantly interrupting with reasons such as drinking, eating, or urinating, and taking significantly longer to do homework. Some children may stare at one place, wander off, drift off, look at the teacher, but don’t know what is going on in their minds. When the teacher asks a question, the child often does not know what the question is about. Attention deficit is a necessary symptom for this disorder. Hyperactivity is another common symptom. The symptoms are increased activity, excessive quietness, running back and forth or small movements, inability to sit still in the classroom, often wriggling in the seat, or stand up, and in severe cases leave the seat and walk, or leave the classroom without permission. Talk a lot, make a lot of noise, interrupt, cause trouble, and interfere with classroom discipline in order to attract the attention of others. Likes to play dangerous games and often loses things. There are two types of hyperactivity: (1) Persistent hyperactivity. The child’s hyperactive behavior can be seen at school, home and other occasions, often more serious. (2) Situational hyperactivity. The hyperactive behavior is only in a certain situation (mostly at school), but not in another situation (at home), and various functions are less impaired. (3) Impulsivity Unstable emotion, easily provoked impulsive, capricious, poor self-control. Easily overexcited by external stimuli and easily frustrated. Behavior without considering the consequences, appearing dangerous or destructive behavior, and will not learn a lesson afterwards. Fourth, learning difficulties mainly manifested as low academic performance. Children with ADHD have normal or basically normal intelligence, and learning difficulties are related to inattention and hyperactivity. The time when learning difficulties appear is determined by the level of intelligence and the severity of ADHD. Children with severe ADHD with low to moderate intelligence can develop learning difficulties early in their school years. Those with higher intelligence and milder ADHD symptoms may have learning difficulties only in middle school. About half of the children with neurological developmental disorders have neurological soft signs, such as clumsy rapid rotation movements, uncoordinated ataxic activities, inability to walk in a straight line, difficulty in standing with eyes closed, positive finger-nose test, inflexible fine movements, and some children may have visual-motor disorders and spatial position perception disorders.