Hyperactivity is defined by displaying these symptoms: often fidgets with hands and feet or squirms in seat; often leaves seat in classroom or in other situations in which remaining seated is expected; often runs about or climbs excessively in situations in which it is inappropriate (in adolescents or adults, may be limited to subjective feelings of restlessness); often has difficulty playing or engaging in leisure activities quietly; is often "on the go" or often acts as if "driven by a motor"; often talks excessively. Impulsivity is characterized by a person that: often blurts out answers before questions have been completed; often has difficulty awaiting turn; often interrupts or intrudes on others (e.g. butts into conversations or games).

             Since the 1940s, psychiatrists have applied various labels to children who are hyperactive and inordinately inattentive and impulsive. Such children have been considered to have "minimal brain dysfunction," "brain-injured child syndrome," "hyperkinetic reaction of childhood," "hyperactive child syndrome" and, most recently, "attention-deficit disorder." The frequent name changes reflect how uncertain researchers have been about the underlying causes of, and even how to precisely diagnose the disorder. There have been extensive studies done on the topic of ADHD, and many conclusions have been drawn from those studies. .

             ADHD is 5 to 7 times more common in boys than in girls; possibly because boys are genetically more prone to disorders of the nervous system. About 1% to 3% of the school-aged population has the full ADHD syndrome, without symptoms of other disorders. Another 5% to 10% of the school-aged population have a partial ADHD syndrome or one with other problems, such as anxiety and depression present. Another 15% to 20% of the school-aged population may show intermittent behaviors suggestive of ADHD. A diagnosis of ADHD is not warranted if these behaviors are situational, do not produce impairment at home and school, or are clearly identified as symptoms of other disorders (Barkley, 1990, p.