ADHD is the most common psychological and behavioral disorder of childhood, mostly in boys, with three core symptoms: attention deficit, hyperactivity and impulsivity. So, how can you tell if your child has ADHD? 1, attention deficit: the presence of 6 (or more) of the following symptoms, lasting at least 6 months, reaching a level disproportionate to development, and significantly affecting social, academic, and vocational activities. Older adolescents and adults (≥17 years of age) need to meet at least 5 of the following symptoms (1) is often careless, sloppy, and inattentive to detail when completing homework, at work, or performing other activities; (2) often has difficulty maintaining attention while completing tasks or play activities; (3) often acts as if he or she does not hear when addressed directly; (4) has difficulty following instructions and requests, resulting in inability to complete homework, chores, or other work tasks; (5) often has difficulty organizing (6) often avoids, dislikes, is unwilling to do, or does things that require constant mental effort; (7) often loses things needed in learning and activities; (8) often easily distracted by extraneous stimuli; (9) often forgets things in daily activities. (2) Hyperactivity and impulsivity: The presence of six (or more) of the following symptoms, lasting for at least six months, reaching a level incompatible with developmental level, and significantly interfering with social, academic, and vocational activities. (1) frequently has trouble sitting, moving hands and feet, or squirming in his or her seat; (2) frequently leaves his or her seat in the classroom or at other times when seating is required; (3) frequently runs or climbs up and down in situations where he or she should not be moving; (4) is constantly busy, as if “driven by an engine”; (5) frequently talks a lot, and talks endlessly; (6) has a history of being “too busy”; and (7) has a history of being “too busy”. (6) often answers questions before they are finished; (7) often has difficulty waiting for his/her turn in order; (8) often interrupts others or forces others to accept him/her. Symptoms of several aspects of inattention and hyperactive impulsivity appear before age 12 and are present in two or more settings (e.g., at home, school, and work, with friends and relatives, and while engaged in other activities). The symptoms interfere with or reduce the social and academic quality of the affected child. However, it is important to exclude that these symptoms do not occur in the course of schizophrenia or other psychiatric disorders and cannot be explained by other psychiatric disorders.