Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disability. It is characterised by attention skills that are developmentally inappropriate, impulsivity, and, in some cases, hyperactivity. ADHD characteristics often arise in early childhood yet almost 50% of children with this disorder are never diagnosed.

There is a fair amount of confusion among both parents and professionals regarding Attention Deficit Hyperactivity Disorder. This is in part due to an evolving definition of the disorder as well as a change in nomenclature. To further complicate matters, there continues to be a difference of opinion not only in the labelling of the disorder, but also in the definition between North American professionals and professionals in the United Kingdom where many Singaporeans go for additional training. This article will reflect the American perspective.

The DSM IV (1994) acknowledges that not all children who have primary problems with attention, organisation and distractibility also have developmentally abnormal levels of activity and impulsivity. Categories include ³Attention-Deficit/Hyperactivity Disorder, Combined Type², ³Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type².

Between 3-5% of children have disorder with an approximate male to female ration of 3:1.

ADHD is a disorder that is characterised by developmentally inappropriate attention; impulsivity and occasionally hyperactivity. Problems with attention can include difficulties focussing attention selectively. Children demonstrate distractibility and have difficulty sustaining attention. In addition, there are problems with reasoning, problem solving, and general problems solving ability. Impulsive ADHD children often act without thinking. They frequently touch, talk, provoke or tease at inappropriate moments. They are seen as emotionally immature, dependent and emotionally volatile. These children with hyperactivity may demonstrate an inappropriate degree of gross motor activity in certain situations. They may demonstrate poor fine motor skills as well as gross motor clumsiness. They are often fidgety even when seated. Visual motor coordination is often poor. As a result of these difficulties, individuals with ADHD often demonstrate diminished social adaptation and effectiveness. Schoolwork becomes a constant trial for children with ADHD. They often perform poorly on classroom tests and examinations is spite of normal or above-average IQs. Attentional problems interfere with the concentration necessary to learn and lack of follow through interferes with tasks that require time in preparation. This leads to erratic classroom performance. Even when motivated, these individuals make careless mistakes, turn in sloppy papers, lose assignments and show an inability to organise themselves to carry out self-paced assignments.

ADHD individuals characteristically display maladaptive behavioural styles in the classroom. Teachers complain that these children are often disruptive not only to themselves but to others because of negative verbalisations, noise making, physical contact with others and other off task behaviour. Perhaps as a result of their frustration, failure and criticism by parents and teachers, these children often appear discouraged, demoralised and unmotivated.

Diagnosis of ADHD

The diagnosis of ADHD is rarely done simply in an office setting. Children with ADHD often look quite normal in a highly structured one to one setting. Rather, information is gathered that night support the diagnosis from multiple informants. At the very least, this must include the primary caretakers and school personnel. Standardised rating scales are useful tools in collecting data. A full developmental history is obtained as well as a detailed description of current levels of adaptation socially, emotionally, behaviourally and intellectually. Finally, information regarding the possible family history for psychiatric disorders and an understanding of the family level of function is made. It is important to understand which parenting methods have been tried and how they have worked. As in any psychiatric interview, associated stressors are examined. A Child Psychiatrist then examines the child individually. A mental status exam is performed as well as a neurological exam. The Psychiatrist observes for frequent co-existing disorders such as Specific Learning Disorders, Learning Disorders, Oppositional Defiant Disorder, Conduct Disorder, Depression.

Children and adolescents with ADHD can be difficult to live with although they are often loveable, caring and considerate. Parents and siblings can often experience stress as a result of ADHD related behaviours. Teachers may complain to the parents of their child's behaviour. Difficulties occur with friends and parents may find that they are increasingly socially isolated. Parents often feel frustrated and helpless. They may try many models of discipline but none seem to work.

Parents may be at risk of experiencing excessive stress for 2 reasons. First, it is a challenge to raise a child with ADHD. Second, there is a hereditary predisposition to the disorder. That is these parents have a higher rate of ADHD and psychiatric problems than those of the general population. Studies show that up to 20% of mothers and 30% of fathers of children with ADHD also have ADHD. There is also a greater chance of ADHD among biological siblings of ADHD children; 30 to 35% may have ADHD. It is not surprising that parents of children with ADHD experience greater stress in their role as caretakers, lower levels of self-esteem, higher levels of depression, more self blame and greater social isolation than do parents of normal children.

Parents of children with ADHD are more likely to experience a variety of psychiatric disorders than are parents of normal children. These disorders include conduct disorders and antisocial behaviour, alcoholism, mood disorders and depression and learning disabilities.

Genetic, neurochemical and other factors have been found to influence the occurrence of ADHD. The current view is that there is a biological-neurological aetiology of DHD that is manifested via psychological and social factors. A complete review of all these factors is outside the scope of this article. Family studies, twin studies, and adoption/foster home studies suggest an important genetic contribution to ADHD.

In addition, natal, perinatal and socio-environmental factors may impact on the developing foetus. Examples of these are poor nutrition, absence of prenatal care, metabolic or toxic factors, infections and stress. Infections, metabolic disorders, exogenous toxins, and deficiency of diet can also contribute to a higher incidence of ADHD. Of great concern is the contribution of maternal substance use during pregnancy. Clearly Foetal Alcohol Effect and Syndrome contribute to the incidence of the disorder.

In 1990, landmark study by researchers of the National Institute of Mental Health in the USA documented the neurobiological underpinnings of ADHD through brain imaging. The frontal cortex and areas of the brain responsible for attention, handwriting, motor control and inhibition responses are less active in individuals with ADHD.

Approximately 80% of children with ADHD will meet the criteria for this disorder in adolescence. Approximately 60% of children with ADHD will continue to have symptoms of their disorder into adulthood. Previously, it was believed that ADHD resolved itself before or during adolescence. A full description of Adult ADHD is beyond the scope of this article.

Treatment of ADHD

The treatment of ADHD requires a multidisciplinary approach. The treatment team can and often includes a Child Psychiatrist, a Psychologist or social worker who provides parent training in behavioural techniques and social skill training for the child, educators and parents. At other times a Speech Language Therapists, experts in Special Education and Educational Psychologists may also be involved.

The mainstay of treatment for Children with ADHD is pharmacotherapy. However, medication should always be used with a well coordinated approach that includes behavioural therapy, social skill training and parent education, in addition to modifying the learning environment. Medications that have been shown to be useful for ADHD include the stimulants (methylphenidate, dextroamphetamine and pemoline), tricyclic antidepressants, monoamine oxidase inhibitors and certain specific antidepressants such as bubrprion. Other medicines include clonidine and on occasion major tranquillisers.

There is not a great deal of evidence that behaviour modification alone is very effective for the treatment of ADHD. However, when combined with the use of pharmocotherapy, it can be a very powerful tool. Traditional supportive psychotherapy tends not to be an effective treatment of ADHD. Cognitive behavioural therapies which train children to use self verbalisation and self instruction to help themselves focus on the problem and develop better coping styles may be promising. However, it is very time intensive, and some studies show that it fails to generalise outside of the treatment setting.

Treatments that have not been shown to be effective with ADHD include diet, sensory integration therapy, chiropractic treatments, ocular and auditory exercises and EMG biofeedback.

There has been some evidence that a significant proportion of ADHD children go on to become inattentive, labile, impulsive adults with psychiatric problems. Others go on to be highly creative and productive professionals. Unfortunately, it is impossible to predict the future for each individual child. The unknown outcome of ADHD can be helpful in persuading the family to maintain follow-up on a regular yearly basis, even if the medications are stopped.