* Up to 5 per cent of all school-age children in England and Wales suffer some form of attention deficit hyperactivity disorder - although researchers say it is under-diagnosed
* Other researchers believe that to say 5 per cent have some form of ADHD is "syndrome-itis" and gives a label to what used to be called naughtiness
* It should not be diagnosed in a child under seven as ADHD-type behaviour can be part of the normal development a child goes through and grows out of
* The condition has become the most researched area in behavioural psychiatry
* It is a lifelong condition and affects people of all ability levels
Photographs: Photonica; Wellcome. Additional research: Tracey Thomas. ADHD (attention deficit hyperactivity disorder) is an issue that polarises people. As with dyslexia 10 years ago, it provokes a crude nature versus nurture response. Those who support the label argue that ADHD is a condition with a bio-medical pedigree that requires specialised treatment, including medication. Detractors condemn what they see as the drugging of boisterous children in need of no more than firm discipline and a run around the park. But most schools these days have a dyslexia policy and they must now steer a path through the ADHD controversy as research suggests most teachers are likely to have at least one child in their class displaying symptoms of hyperactivity, inattentiveness or both, severe enough to seriously impede learning. Whether or not such children have a diagnosis and whether or not they receive medication, schools are increasingly realising they must be ADHD-aware if they have pupils' best interests at heart.
What is ADHD?
Attention deficit hyperactivity disorder is the term given to a condition affecting children in three main areas:
* Hyperactive behaviour
* Impulsive behaviour
* Difficulty paying attention.
These difficulties can continue as the children grow up, sometimes developing into aggressive and delinquent behaviour. ADHD often occurs alongside learning disorders, unusually defiant behaviour (oppositional defiant) and conduct disorders, anxiety, depression and tic disorders.
Children with ADHD who suffer from short-term memory problems and have difficulty internalising rules are at risk of underachievement, peer rejection, substance abuse and truancy. Some children suffer less from hyperactivity but have significant problems with concentration and attention and are often described as having ADD (attention deficit disorder), a condition that can easily be overlooked in a busy classroom as those affected tend to be quiet and dreamy rather than disruptive. ADHD is unrelated to intelligence and can affect children of all ability levels.
How long has it been recognised?
An early and entertaining literary reference to ADHD probably comes from the 17th-century English dramatist John Dryden, who described in his satirical poem Absolon and Achitophel a character called Zimri (Duke of Buckingham) as doing "everything by fits and starts and nothing long and in the course of one revolving moon was kymist, fiddler, statesman and buffoon". Scottish-born physician Alexander Crichton published an account of "morbid inattentiveness" in 1798, not dissimilar from the ADHD diagnosis formulated by the American Psychiatric Association in 1994 and now widely used. This describes behavioural symptoms of inattention, impulsiveness and hyperactivity to a degree that significantly interferes with education or occupation, family and peer relations.
How many people does it affect?
The most recent and reliable figures from the National Institute for Clinical Excellence (NICE) in 2000 show that 1 per cent of children (about 73,000 in England and Wales) suffer severe ADHD (affected by all three aspects - hyperactivity, inattention and impulsiveness), with up to 5 per cent of all school-age children (366,000) suffering some form of the condition. Small-scale studies show that half of children classed as having emotional and behavioural difficulties, and up to 70 per cent of the prison population, may have ADHD. Some researchers argue that ADHD is under-diagnosed.
What is the gender divide?
About four times as many boys as girls display symptoms of impulsivenesshyperactivity while more girls than boys tend to suffer from inattentiveness.
What does the child with ADHD look like in the classroom?
Unusually high levels of fidgeting and unauthorised movement; a tendency to want to be "on the go"; a tendency to be over-talkative and noisy.
Impulsive children often interrupt others and butt into conversations; they have difficulty waiting their turn to participate in games or in answering questions in class. Inattentive children have extreme difficulty staying on task, starting and finishing schoolwork or following instructions; they can appear sluggish; they seem oblivious and daydream; they appear to be unusually disorganised and forgetful for their age. Hyperactive impulsive children tend to be actively rejected by peers and are at high risk of being excluded.
Inattentive children tend to be neglected by peers, and are more likely to internalise problems and have learning difficulties.
How do you know when it's ADHD rather than poor behaviour?
Many children will at some point behave like children with ADHD, but it is the degree and persistence of behaviours that indicate the condition.
Diagnosis can be a painfully drawn-out process. Paul Cooper, professor of education at Leicester University and director of the Centre for Innovation in Raising Educational Achievement, says the problem is where you draw the line. "An element of judgment is required because it's a complex condition with many links in the chain, dependent on people from several professions co-operating with each other. It's not just a question of a clinician walking into a room and observing a child for half a day." A diagnosis should be applied only when the symptoms are persistent in school and at home, and have serious and debilitating consequences for the life of affected children and those around them. ADHD is considered a lifelong condition, although it can be modified by maturity. It is influenced by biological factors and responds to medication. It should not be diagnosed in a child under the age of seven as ADHD-type behaviour can be part of the normal development a child goes through and grows out of, some later than others; the "terrible twos" can last until a child is five or six.
What are the causes?
ADHD has become the most researched area in behavioural psychiatry. Current theory suggests it has its roots in a disorder of the frontal lobes of the brain, a major function of which is to control our impulses and regulate the ways in which we direct our attention. Disorder in the frontal lobes is thought to impede working memory and the process of "internalised speech", in which possible consequences of behaviour and impulses are weighed up.
Studies have found particularly low levels of activity in the neurotransmitters in this part of the brain among ADHD sufferers, which is why stimulant medication has proved useful. Researchers have also shown that in 70 per cent of cases the neurology is inherited, and that in another 20 to 30 per cent ADHD is caused by brain disease such as encephalitis, brain injury or toxin exposure as a result of drug or alcohol abuse pre or post-natal.
So why is there more of it?
There probably isn't. Research suggests it has always existed, we are just becoming better at recognising it. But experts believe the social factors that exacerbate the symptoms of ADHD have multiplied in recent years, and that the extent to which neurological problems result in behavioural and social dysfunction will be influenced by the person's learning and experience. Positive and supportive experiences can help a person compensate for cognitive difficulties. Family break-up, insecurity caused by a fast-moving consumerist society combined with a testing culture in schools that is less tolerant of non-conformity means children are less able to cope with their ADHD, and the symptoms therefore become more acute.
Is this conclusive?
No. Although an overwhelming body of research seems to support the validity of a diagnosis, it is hotly debated. Critics point to the convenient concentration on a medical model as a way of detracting from bad parenting and bad teaching. For example, Professor Stephen Rose, director of brain and behavioural research at the Open University, accepts a very small number of children - no more than one in 1,000 - may be affected to some extent in this way, but to say 5 per cent have some form of ADHD is "syndrome-itis - giving labels to what used to be called naughty children".
Priscilla Alderson, professor of childhood studies at the Institute of Education, University of London, blames the "enforced inactivity" that society imposes on children. Professor Cooper says practitioners should consider the overwhelming evidence that ADHD is much more than not knowing how to behave - that it is "located within the individual at a much deeper level, a method of engaging with the world analogous to Asperger's or autism".
How long does it take to get a diagnosis?
Child and adolescent mental health services are so overstretched that it can take between six months and two years even to get a consultation - and in some areas, according to ADDISS (The National Attention Deficit Disorder Information and Support Service), the lists are closed. There is no single service for ADHD and no clinical tests exist because social and psychological as well as biological factors are involved. Once a process is in train, a diagnosis can take many months, as it depends on co-operation between professionals from several services. Young Minds, the children's mental health charity, is concerned that overstretched professionals may be pushed into giving a diagnosis before all aspects of the child's behaviour have been thoroughly researched. Conversely, it believes ignorance among professionals about the condition means ADHD "is under-recognised even now".
Is Ritalin the answer?
Research has shown that drugs such as methylphenidate (Ritalin) or dexamphetamine (Dexedrine) that stimulate the parts of the brain that control behaviour do produce short-term benefits. Many parents and teachers comment on the dramatic improvements they have seen. As children calm down they are better able to mix with others and respond effectively to teachers. Ritalin is short-acting, lasting no more than three to four hours at a time, so doesn't stay in the system for long, avoiding problems with build up of residues and tolerance. On the other hand, there is evidence that once the drug wears off there is a "rebound" effect - the ADHD can reassert itself in a marked way which can be distressing for the child and the school. A child's response to the drug must be well-documented by home and school because the medication can create a "zombie effect" if given in the wrong dosage. It can also have side-effects, suppressing appetite and causing growth problems. About 30 per cent of children with ADHD do not benefit from stimulant medication, particularly if they are anxious or depressed.
In the US, 2 to 2.5 per cent of school-age children are prescribed medication, mainly Ritalin, for hyperactivity; in the UK it is under 1 per cent. The increased prescribing of Ritalin is controversial, especially as, according to NICE, there are no proven long-term benefits. At the extreme, it is regarded as a sinister form of social engineering, but even more moderate critics are anxious that it is of less benefit to children than to the people who have to deal with them. Fife and Glasgow education authorities are ahead of the field in producing comprehensive ADHD guidelines; in Fife, children have a monitored medication break so the drug's effectiveness can be monitored with close co-operation between health and education services.
Who should administer Ritalin in school and how?
Many local education authorities have an established protocol, which should include direct communication from the health service to schools, parental agreement and a designated person in school to administer drugs. If any children require Ritalin while at school, they should never be left to their own devices as there is a danger of it getting into the wrong hands.
Ritalin has a street value as an appetite suppressant, particularly with young girls and, as it is essentially an amphetamine, can give a high if it is crushed and snorted.
Does diet help?
Some children with ADHD may react badly to certain combinations of foods including dairy products, chocolate, wheat and, particularly, additives.
The absence of iron as well as deficiencies in zinc, magnesium and some essential fatty acids may be a factor. Other research points to the beneficial effects of omega 3 oils on impulsive behaviour.
The long-term effects Some people do seem to manage their ADHD as they mature, but the lives of others can be blighted. They may have relationship problems, difficulty sustaining or finding work, a vulnerability to substance abuse and reduced life expectancy. They also face an increased risk of a prison sentence or a stay in psychiatric hospital, and involvement in motor accidents.
But some people with ADHD find that the very characteristics that caused problems for them at home and school become advantageous in the world beyond. For example, businessman Richard Branson and comedian Billy Connolly have both made an asset of their hyperactivity and risk-taking.
What can schools do to help?
A recent overview of research on interventions for ADHD by the Queensland University of Technology, Australia, shows that school-based intervention is the most effective in helping ADHD children to engage in the kind of internal dialogue necessary to manage their condition long-term. Schools should not wait until a child has a diagnosis before they try to deal with symptoms, nor should they think that because a child has a diagnosis and medication that the problem is no longer their responsibility. Medication alone is not the way forward. Behaviour management strategies at home and in school are vital.
At Gayhurst primary in the London borough of Hackney, where 40 per cent of children are on the special needs register, a whole-school approach closely involves parents. Children with concentration difficulties or ADHD are set clear, unambiguous, bite-sized targets; parents are consulted over issues such as diet and bedtime routine, the curriculum is given an activity-based focus, the school runs a "circle of friends" system where a child having problems with behaviour is supported by a volunteer peer group that meets weekly.
Fife and Glasgow's ADHD guidelines include an observational checklist for teachers to look in a structured way at what distracts a child, what conditions are the most successful and to liaise accordingly with health professionals. Nurture groups - there are now more than 1,000 in the UK - are another way forward. These are in-school facilities offering a small class (often no more than 12 children) to troubled - and troublesome - children for between two and four terms to be taught by two adults who model supportive relationships. The emphasis is on intensive social learning, respect for and listening to the children and making them feel valued.
Professor Cooper suggests the key teaching skills for dealing with ADHD are:
* Willingness to listen
* Clarity of communication
* Willingness to repeat or paraphrase information without showing exasperation.
Effective strategies include:
* Seating a child in class in a place relatively free from distraction (away from doors and windows) where it's easy to detect if a pupil is not paying attention and where you can intervene without embarrassing the child or interrupting the lesson
* Having a designated quiet place
* Breaking tasks down into small steps
* Giving pupils a clear and simple timetable
* Giving academic, work-related targets rather than behaviour targets
* Giving specific and frequent feedback on work performance
* Getting pupils to work in pairs rather than groups
* Creating opportunities for a pupil to move around.