ADHD

ADHD

What is it?
Attention deficit hyperactivity disorder (ADHD) is the most common childhood-onset behavioural disorder.

Those affected have a greatly reduced ability to maintain attention without being distracted, to control what they're doing or saying (because of impulsivity) and to control the amount of physical activity appropriate to the situation (that is, they're restless and fidgety).

ADHD is also called attention deficit disorder (ADD) or hyperactivity. The disorder shouldn't be confused with normal, boisterous childhood behaviour.

What causes it?

The brain fails to filter the huge amount of stimulation we receive every minute of every day

ADHD may be caused, in part, by an inherited imbalance of neurotransmitters (chemicals that transmit nerves signals in the brain). One of the main problems in ADHD seems to be that the brain fails to filter the huge amount of stimulation we receive every minute of every day.

An affected child is easily distracted and can't process information at a normal rate. The frontal lobes don't work as well as they should with processes such as decision making, and there may be imbalances in the brain chemicals noradrenaline and dopamine.

However, this is a generalisation - brain research shows a variety of different problems in ADHD, with individuals showing their own pattern of behaviour.

Genetic or hereditary factors are important - usually a parent or close relative also has the condition. Twin and genetic studies show several genes are likely to be involved. Evidence of brain dysfunction has been found in brain-imaging studies.

However, research has so far been unable to show consistent neurobiological differences between affected children and normal controls, so the syndrome remains controversial.

Diet may be a factor - parents have long claimed that food additives can aggravate hyperactive behaviour and research by the Food Standards Agency and Southampton University has shown that certain mixtures of artificial food colours, alongside sodium benzoate - a preservative used in ice cream and confectionary - are linked to increases in hyperactivity.

What are the symptoms?
Symptoms include excessively, consistently and involuntarily having difficulty:

Remaining seated when required
Waiting turn in group situations
Following instructions
Playing quietly



Other common symptoms include:

Shifting from one incomplete activity to another
Interrupting others
Engaging in physically dangerous activities without considering the consequences



Not everyone with ADHD has the same symptoms or is affected by each to the same degree. There are three types of people with ADHD:

Predominantly hyperactive-impulsive
Predominantly inattentive
Combined (the majority of ADHD cases)



There's also a fourth type, which doesn't fit into any of the three categories, classified as 'ADHD not otherwise specified'.

These problems are pervasive and debilitating, sometimes to the degree that daily functioning becomes extremely difficult. They can affect education and disrupt family life.

While their intellect may be normal or advanced, more than half of children with ADHD have specific learning disabilities, such as dyslexia. Coping with the symptoms can mean underachievement and poor self-esteem.


Children with ADHD are also more likely to be depressed, anxious and obsessive

Children with ADHD are also more likely to be depressed, anxious and obsessive, and may have some problems with speech, language and coordination.

Other major disorders may accompany ADHD, including oppositional defiant disorder (arguing and intentional defying) and conduct disorder (major antisocial activity).

Hyperactivity may improve at puberty but the problems usually persist in some form throughout adult life - up to 60 per cent of children show ADHD behaviour in adulthood.

Who's affected?
ADHD usually starts at about 18 months, but might not be diagnosed until later, even until adulthood.

It's estimated that ADHD affects five to ten per cent of children and adolescents in the UK, with up to one in 100 severely affected. Symptoms usually develop between the ages of three and seven, with boys more likely to be affected than girls. The condition can run in families.

it's not caused by bad parenting or abuse. The condition may affect one of the parents, however, and interfere with their parenting skills.