They appear not to listen when someone is talking to them, find it hard to wait their turn and can be disruptive in their play. Some children with ADHD can concentrate for longer periods on things which really interest them, for example computer games, but can be easily distracted.
Of course, all children behave impulsively and find it hard to concentrate sometimes. But with ADHD, this behaviour is persistent and occurs wherever the child is, not just in one place such as school or at home. Symptoms usually start when a child is a toddler, and always before they reach the age of six or seven. Children can have ADHD in varying degrees of severity, and sometimes it is found together with other conditions such as dyslexia. But it is important to understand that just because a child is naughty or defiant or aggressive it does not always mean that he or she has ADHD. There may well be other reasons for this kind of behaviour: the child may be anxious or there may be problems in the family or school. ADHD is a distinct condition, part of the make-up of the child.