How common is ADHD?
Estimates vary, both between and within different countries, but ADHD is one of the most commonly-diagnosed behavioural disorders in children and young people.3
- Studies in the UK suggest that ADHD occurs in an estimated 5% of school aged children.1 This means that the average UK classroom will include at least one child with ADHD
- Studies in the United States report higher rates of ADHD,4 possibly due partly to the use of different criteria to diagnose ADHD in the US
- ADHD is more common in boys than in girls, by a ratio of at least three to one5
- Up to two-thirds of children with hyperactivity disorders continue to have problems into adulthood6