ADHD is a common behavioural disorder in children and young people. It usually starts in early childhood and some people will continue to have ADHD as adults. Severe ADHD is sometimes known as 'hyperkinetic disorder'.
The symptoms of ADHD include being:
inattentive – unable to concentrate for very long or finish a task, disorganised, often losing things, easily distracted and forgetful, unable to listen when people are talking
hyperactive – fidgety and unable to sit still, restless (children may be running or climbing much of the time), talking constantly, noisy, having difficulty doing quiet activities
impulsive – speaking without thinking about the consequences, interrupting other people, unable to wait or take their turn.
Not all people with ADHD have all these symptoms, and everyone can be inattentive, hyperactive or impulsive some of the time, particularly children. But a person with ADHD has symptoms most of the time that can seriously affect their everyday life. They may also be clumsy, unable to sleep, have temper tantrums and mood swings and find it hard to socialise and make friends.
It can sometimes be difficult to work out if a person has ADHD because there are conditions that can cause similar behaviour, such as conduct disorder in children or personality disorder in adults. The person may also have other conditions, for example, conduct disorder, anxiety or learning difficulties, as well as ADHD.