ADHD - "A DIFFICULT DIAGNOSIS WITH DIFFICULT CHILDREN"

by Dr Geoffrey D Kewley, Consultant Paediatrician, The Ashdown Hospital, Haywards Heath, Sussex

Experts are expressing concern that Attention Deficit Hyperactivity Disorder is under-diagnosed in the UK. Geoffrey Kewley looks at the problems facing GPs when presented with children displaying a range of symptoms, often difficult to interpret, and the current therapies in use.

Attention Deficit Hyperactivity Disorder (ADHD) can present with either behavioural or academic problems.

Symptoms

Symptoms are those of poor concentration, easy distractibility and impulsiveness, often associated with hyperactivity. This can lead to a varying degree of loss of self esteem, and behavioural or conduct problems, as well as school failure.

Very often these children are diagnosed as dyslexic or having behavioural conduct disorder, and parents are often blamed for the symptoms, thus tending to aggravate the situation.

A detailed assessment is essential and consideration of various treatment options, including educational and psychological, or medication. Where medication (usually methylphenidate) is used, there can frequently be seen a remarkable change in a child's performance leading to improved concentration, less distractibility, and a marked improvement in self esteem and behaviour.

ADHD is characterised in children who:

• often fidget
• are easily distracted
• have difficulty in waiting turns
• often blurt out answers to questions before they are completed
• have difficulty following through instructions

In addition, such children:

• have difficulty in sustaining attention to tasks, often shifting from one uncompleted activity to another
• cannot play quietly
• talk excessively
• often interrupt or intrude on others
• often seem not to listen
• engage in physically dangerous activities without considering possible consequences

Diagnosis

While the diagnosis of ADHD is common in North America, it is much less so in the United Kingdom. However, it is likely that the incidence in the UK is much higher than previously recognised.

The diagnosis of behavioural problems, dyslexia or learning problem, is often made in the UK, whilst the same child in North America would have been diagnosed as ADHD. The reasons for this have been explored by Taylor.

Part of the problem is the difference between the World Health Organisation criteria ICD-10, which is commonly used in Europe and that of the DSM-III-R(American Psychiatric Association 1987), which is used primarily in the United States.

The ICD-10 diagnostic criteria for hyperkinetic disorders require pervasive inattention and restlessness (across situations and persistent over time) demonstrated at home and school, and very much relate to the concept of hyperactive behaviour.

The DSM-III-R classification puts much less on hyperactive behaviour, recognising that approximately 30 per cent of these children are not hyperactive, but have problems in inattention and impulse control, and that the hyperactivity is not always pervasive, i.e. that, when examined in a consulting room, a child may be able to sit still and pay attention especially in a one-to-one situation, but that in the classroom this may not be the case.

A study by Rutter et al showed a particularly low incidence of hyperactivity, identifying only two cases of hyperactivity in nine and ten year olds among 2,199 children. Taylor notes that there is a twentyfold difference in the frequency with which hyperactivity is diagnosed between parts of the United States and parts of England, for instance.

There is a voluminous body of literature on ADHD, mostly from North America, where two to five per cent of the child population is diagnosed in this way, and up to one pert cent of the school population is on psycho-stimulant medication. Therefore, it becomes critical to decide whether or not the condition is being under- or mis-diagnosed in the United Kingdom, diagnosed inappropriately in North America, or whether the two populations are different.

ADHD in children of school age can affect behaviour, social or emotional adjustment, and academic performance. The aim of this paper is to clarify the situation for general practitioners, paediatricians and psychologists.

There are a wide range of symptoms with which these children can present, but they broadly fall into either behavioural and/or educational difficulties.

Behavioural difficulties

The hallmarks of attention deficits are inattention, easy distractibility and impulsiveness. The children may be distracted by internal thought processes, as well as outside distractions.

Impulsiveness, often leading to danger for the child, restlessness, and hyperactivity, are prominent features. Other problems include difficulty in socialising and in sustaining mental effort, leading to inconsistency. The parents often say that the child is unable to sit still, does not pay attention, and is reluctant to follow instructions.

There is frequently a suggestion of the early onset of hyperactivity, either in utero or as a difficult infant. The child runs before it walks, is a difficult toddler, and often in trouble at playgroup because of a high activity level. Many of the symptoms of attention deficit disorders are part of a normal spectrum of childhood behaviour, and it is often difficult to differentiate whether or not they are excessive.

Attention problems may occur in association with specific learning disorders, with subtle speech and language disorders, mental retardation, autism, and a number of psychiatric diagnoses.

Children with Tourette Syndrome have attention problems and between 10 and 40 per cent of children with learning disabilities also have attention problems. The interface between attention problems and specific learning difficulties is unclear. There is a relationship between otitis media in early childhood, perinatal problems and congenital infection, and subsequent attention impairment.

Educational difficulties

Academic problems occur when children who, because of their shortened attention span, have difficulty staying on task, focusing and retaining attention, tending to daydream and readily distract.

They find it hard to retain information, and have associated co-ordination difficulties, leading to problems with sports activities at school and with writing, as well as speech and/or specific learning difficulties.

Many are hyperactive and are frequently impulsive and a danger to themselves. They are readily frustrated with aggressive outbursts and have difficulty in adjusting to new situations. Low self-esteem leads to frustration and further behavioural problems.

History

Symptoms of ADHD tend to persist throughout childhood, often not responding to usual disciplinary, dietary or teaching methods. The history should include the features that concern the parents, the age at which symptoms started, whether they occurred in infancy or even in utero, and whether there are any relevant tensions within the family.

Examination

Physical examination assessment should specifically look for dysmorphic features, neurocutaneous stigmata, absence episodes, soft neurological signs, and evidence of poor co-ordination.

Assessment of neuro-developmental progress, including language, visual and auditory ability, should be made. Other causes of the symptomatology, including epilepsy, developmental delay, and psychiatric disorders should be considered.

Rating scales are used because of the pervasiveness of the ADHD disorder and the fact that often, in a one-to-one situation in the consulting room, the symptoms are not so noticeable.

It is important to seek the parents' and the teachers' views. A useful way of doing this is through one of the various rating scales, of which the Connors or Achenbach Parent and Teacher Rating scales are widely used.

Apart from helping with the initial diagnosis, the rating scales are effective in serial assessment and evaluation of treatment. They measure the diagnostic criteria for ADHD in a more referenced way. Teacher rating scales are often considered to be more reliable. However, they do depend on the co-operation of the teachers and an awareness on the teachers part of the problems of attention deficit disorder.

Psychometric assessment is an essential part of the diagnostic evaluation. Discrepancy between intelligence tests and the actual level of academic achievement is useful in assessing whether or not the child is reaching his/her full potential. The Weschler Intelligence Scale for Children (WISC-R) and the British Ability Scales are the most commonly used IQ tests.

In addition to the IQ scores, an assessment of verbal comprehension, perceptual organisation, and freedom of distractibility is obtained involving arithmetic digit span and coding. Assessments of attention difficulties before and after treatment are often useful, using continuous performance tests.

ADHD can be managed with a number of management techniques available, depending on the severity and type of symptom.

Management

Behavioural techniques at home are useful in altering the daily routine to allow for structure and definite periods of play. Avoidance of over-stimulating situations and long, tiring, activities is useful. Tasks should be broken into smaller components, and instructions given individually and clearly. The behavioural limits need to be identified prior to the activity being started.

Behavioural techniques, which need to be modified according to the child and his/her age, include positive reinforcement, role modelling by parents, and time out.

Behaviour often becomes worse initially when such strategies are implemented. Behavioural programmes are difficult with these children, because they become bored with them and they rapidly become less effective.

The guidelines need to be redrawn fairly frequently, and parents should try to avoid conflict and frustration and build up the child's self-esteem. It is better to set small, frequent goals rather than one long schedule.

Educational strategies are important where there are learning and behavioural difficulties at school. Good communication is essential between the paediatrician, the teachers, parents, and the child.

Seating the child towards the front of the class where there is less distraction and easier teacher/child eye contact is important. The teacher should try to give the child other activities at intervals to break up the concentration time. Instructions should be brief with visual reinforcement. Long and multiple instructions should be avoided. There are often associated learning disabilities which may require schooling or resource help.

Medication

Medication is often extremely effective in controlling ADHD symptoms. Psycho-stimulants are the most commonly used, and are frequently extremely effective in controlling the symptoms and giving the child and family some stability while other educational and behaviour management techniques are put in place.

They should not be used in isolation without employing educational or behavioural strategies.

Methylphenidate is the most widely used psycho-stimulant medication and is a dopamine agonist. A low dose (often half a tablet) each morning should be started for a few days to be certain there are no side-effects. The dose can then be gradually increased.

The medication usually only last for three to five hours, and as it wears off there is often a rebound worsening. The next dose should be given before this happens. The dose is extremely variable and individual and can range from 0.3mg/kg to 0.7mg/kg. One of the common causes of apparent failure of methylphenidate is the use of an inappropriate dosage or frequency of medication.

Often, children with educational and attention problems only, without hyperactivity, require a lower dose. The dosage can be either one in the morning and the second at lunchtime, or a third dose can be given after school to enable homework to be done.

Homework may be possible without methylphenidate because it is a one-to-one situation. When starting methylphenidate, it should only be with informed parent consent.

The behavioural or academic difficulties are often markedly improved, such that a child who is achieving far below his or her potential starts to behave and perform much more appropriately.

There is a need for frequent telephone contact between clinician and parents over the first few weeks. Moreover, there should be a review, with the child and the parents, after about six weeks, in order to assess the situation, any improvement, side-effects, or to fine tune the dosage of the medication to maximum effect. Regular rating scale assessment is very useful.

More than 80 per cent of children with ADHD respond well to psycho-stimulants. Those children with conduct disorder and where there is a mixture of attention problems and/or an associated learning problem, respond less well.

The dosage of the psycho-stimulant should be continued on the lowest dose at which there is perceived adequate response.

An occasional medication holiday is sometimes suggested. Except in those children where there is only a schooling problem and where medication can be omitted at weekends, most of the children are treated continuously.

Improvement

There is usually rapid improvement in concentration, distractibility and impulsiveness. Other symptoms such as poor socialisation and self-esteem are usually much improved within three to six months, as the child starts to receive more praise and realises that he/she is starting to achieve more to the proper level of ability. There will also be less aggression and frustration.

The improvement of the symptoms is more dramatically apparent for parents. Family stress then diminishes, and it is then possible to look at more effective behavioural management techniques and individual or family therapy, where appropriate, can be initiated.

Other medications used in this condition include Dextroamphetamine, which has similar action and side effects to methylphenidate but is less commonly used. Pamoline, tricyclic antidepressants, and clonidine have also been used with varying success rates.

Concerns have been express about the side-effects of such drugs, especially the possibility of addiction, although a number of authors have shown no evidence of increased incidence of addiction.

Without treatment, many of these children, especially those with hyperactivity, can end up with problems of major antisocial activity, including addiction.

Other side effects that have been observed are of a mild nature (e.g. appetite suppression). But occasionally behavioural change, rashes, difficulty in sleeping, or tics, have been noted.

In the case of anorexia, where significant weight loss is observed, methylphenidate should be ceased. Growth delay has been reported but is rarely seen. Growth rates should be measured regularly.

Other interventions include social skills training, psychotherapy, cognitive training, and parent behaviour management training.

Long-term prevalence

There is some controversy regarding the long-term outcome of ADHD and whether or not medication affects this. In contrast to earlier data it is now felt that attention deficit symptoms persist into adolescence and adults in about 60 per cent of cases, and that ADHD in adults is a significantly under-recognised cause of psychiatric morbidity and can be the forerunner of depression, job instability, relationship problems, alcoholism etc.

Conclusion

ADHD is almost certainly under-diagnosed in the UK. Professionals need to consider it in the differential diagnosis of children with disturbed behaviour and academic problems, especially when there are elements of inattention, distractibility, and impulsiveness without hyperactivity.

Children who are diagnosed as being either dyslexic or to have a conduct disorder, on more appropriate examination, may be found to have an attention problem as their main difficulty.

The diagnosis is frequently missed and parents may be blamed for difficulties where, in many cases, they have done exceptionally well to cope with living with such children. A medical, educational, and psychometric evaluation is essential.

Further research is required with regard to the true incidence of attention problems in children in the UK. Assessment and treatment should be carried out by those who are familiar with the condition and the various therapeutic strategies.

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