Attention deficit hyperactive disorder (ADHD) attention deficit disorder in

Attention deficit hyperactivity disorder (ADHD) is a condition that affects people's behaviour. People with ADHD can seem restless, may have trouble concentrating and may act on impulse.

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 under 12 years old, but sometimes it's diagnosed later in childhood.

The exact cause of attention deficit hyperactivity disorder (ADHD) is unknown, but the condition has been shown to run in families.

Other factors suggested as potentially having a role in ADHD include:

• being born prematurely (before the 37th week of pregnancy)
• having a low birthweight
• smoking or alcohol or drug abuse during pregnancy

ADHD can occur in people of any intellectual ability, although it's more common in people with learning difficulties.

The main signs of inattentiveness are:

• having a short attention span and being easily distracted
• making careless mistakes – for example, in schoolwork
• appearing forgetful or losing things
• being unable to stick to tasks that are tedious or time-consuming
• appearing to be unable to listen to or carry out instructions
• constantly changing activity or task
• having difficulty organising tasks

The main signs of hyperactivity and impulsiveness are:

• being unable to sit still, especially in calm or quiet surroundings
• constantly fidgeting
• being unable to concentrate on tasks
• excessive physical movement
• excessive talking
• being unable to wait their turn
• acting without thinking
• interrupting conversations
• little or no sense of danger

These symptoms can cause significant problems in a child's life, such as underachievement at school, poor social interaction with other children and adults, and problems with discipline.

• anxiety disorder 
• oppositional defiant disorder (ODD) – this is defined by negative and disruptive behaviour, particularly towards authority figures, such as parents and teachers
• conduct disorder – this often involves a tendency towards highly antisocial behaviour, such as stealing, fighting, vandalism and harming people or animals
• depression
• sleep problems 
• autistic spectrum disorder (ASD) – 
• dyspraxia – a condition that affects physical co-ordination
• epilepsy – a condition that affects the brain and causes repeated fits or seizures
• Tourette's syndrome – a condition of the nervous system, characterised by a combination of involuntary noises and movements (tics)
• learning difficulties – such as dyslexia

Diagnosing ADHD in children depends on a set of strict criteria. To be diagnosed with ADHD, your child must have 6 or more symptoms of inattentiveness, or 6 or more symptoms of hyperactivity and impulsiveness.

To be diagnosed with ADHD, your child must also have:

• been displaying symptoms continuously for at least 6 months
• started to show symptoms before the age of 12
• been showing symptoms in at least 2 different settings – for example, at home and at school, to rule out the possibility that the behaviour is just a reaction to certain teachers or to parental control
• symptoms that make their lives considerably more difficult on a social, academic or occupational level
• symptoms that are not just part of a developmental disorder or difficult phase, and are not better accounted for by another condition