Attention deficit hyperactivity disorder (ADHD, similar to hyperkinetic disorder in the ICD-10) is a psychiatric disorder of the neurodevelopmental type in which there are significant problems of attention, hyperactivity, or acting impulsively that are not appropriate for a person's age. These symptoms must begin by age six to twelve and persist for more than six months for a diagnosis to be made. In school-aged individuals inattention symptoms often result in poor school performance.Despite being the most commonly studied and diagnosed psychiatric disorder in children and adolescents, the cause in the majority of cases is unknown. It affects about 6–7% of children when diagnosed via the DSM-IV criteria and 1–2% when diagnosed via the ICD-10 criteria. Rates are similar between countries and depend mostly on how it is diagnosed. ADHD is diagnosed approximately three times more in boys than in girls. About 30–50% of people diagnosed in childhood continue to have symptoms into adulthood and between 2–5% of adults have the condition. The condition can be difficult to tell apart from other disorders as well as that of high normal activity.ADHD management usually involves some combination of counseling, lifestyle changes, and medications. Medications are only recommended as a first-line treatment in children who have severe symptoms and may be considered for those with moderate symptoms who either refuse or fail to improve with counseling. Long-term effects of medications are not clear and they are not recommended in preschool-aged children. Adolescents and adults tend to develop coping skills which make up for some or all of their impairments.ADHD, its diagnosis, and its treatment have been considered controversial since the 1970s. The controversies have involved clinicians, teachers, policymakers, parents, and the media. Topics include ADHD's causes and the use of stimulant medications in its treatment. Most healthcare providers accept ADHD as a genuine disorder, and the debate in the scientific community mainly centers on how it is diagnosed and treated.