Attention deficit hyperactivity disorder (ADHD) is a behavioural disorder that includes symptoms such as inattentiveness, hyperactivity and impulsiveness.

Symptoms of ADHD tend to be noticed at an early age and may become more noticeable when a child's circumstances change, such as when they start school.

Most cases are diagnosed when children are 6 to 12 years old.

The symptoms of ADHD usually improve with age, but many adults who were diagnosed with the condition at a young age continue to experience problems.

People with ADHD may also have additional problems, such as sleep and anxiety disorders.