by Dr. Milton Lum
Attention deficit hyperactivity disorder (ADHD) comprises behavioural symptoms of inattentiveness, impulsiveness and hyperactivity. People with ADHD have a short attention span, are easily restless, get distracted easily and fidget incessantly.
Whether ADHD is an extreme form of normal behaviour, or part of a separate range of behaviour, is not well understood.
It is estimated ADHD affects about 3-9% of schoolgoing children and young people, and about 2% of adults. It is the most common behavioural disorder in many countries.
ADHD starts at an early age and becomes obvious when the child's situation changes, e.g. starting school. It is more common in males. Whether ADHD can occur in adults without it occurring in childhood has not been elucidated.
It is estimated that at age 25, about 15% of childhood ADHD patients still have a full range of symptoms, and 65% have symptoms affecting their daily lives.
What Causes ADHD?
The causes of ADHD are not well understood. It is believed to be due to a combination of genetic and environmental factors.
ADHD occurs in families. Both parents and siblings of a child with ADHD are 4 to 5 times more likely to have ADHD.
Brain function in ADHD is different from people without the condition. It is believed that there is impaired function of the brain chemicals that transmit messages. Activities in the sections of the brain that control attention and activity appear to be less.
There are also findings that indicate impaired function of the frontal lobes that control decision-making, and altered levels of chemicals like dopamine and noradrenaline.
Pregnant smokers and alcohol and drug abusers have an increased risk of giving birth to a child with ADHD.
Males are more likely to be diagnosed with ADHD. This may be because loud and disruptive behaviour are more noticeable in males. It may also be that the diagnosis is missed in females because they are more likely to have attention deficit disorder (ADD), which is a type of ADHD.
Although there is insufficient evidence linking television to ADHD, it is believed that watching tv for several hours a day by children below 3 years of age could be a contributing factor to attention problems and ADHD later.
There are suggestions of associations between ADHD and common food allergens like milk and wheat. Other suggested causes are premature birth (before 37 weeks of pregnancy), low birth weight, brain damage in utero or in the first few years of life.
Symptoms of the Disease
The features of ADHD can be classified into 2 : inattentiveness, and impulsiveness and hyperactivity.
There are 3 types of ADHD, ie mainly inattentive, mainly hyperactive-impulsive, and combined.
The combined type is the most common. The mainly inattentive is also known as ADD. As females are more likely to have ADD, it is possible that the condition is more common than thought because of underdiagnosis.
The features of inattentiveness are a short attention span; easy distraction; forgetfulness; carelessness; inability to concentrate, carry out instructions and carry out time-consuming tasks; and constant changing of activity.
The features of impulsiveness are acting without thinking; interrupting conversations; inability to wait for a turn; breaking of rules; and inability to appreciate danger.
The features of hyperactivity are inability to stay still; continuous fidgeting; excessive movement and talking; and inability to carry out tasks.
ADHD is associated with other conditions like epilepsy, involuntary movements and sounds, sleep disorders, learning difficulties, anxiety disorders, depression, and conduct disorders, which is usually associated with antisocial behaviour.
However, there is no effect of ADHD on intelligence.
The features of ADHD in adults are more subtle. They include carelessness, forgetfulness, restlessness, inability to focus or prioritise, irritability, mood swings, risk taking and poor organisational skills. There may be problems in respect of relationships, drugs, employment and crime.
ADHD is associated with obsessive compulsive, bipolar and personality disorders.
There is no single diagnostic test for ADHD. If the condition is suspected, an appointment with the doctor is advisable.
The doctor will ask about the symptoms and its impact on the child's quality of life, any changes in social circumstances, family history of ADHD, other health problems and any functional effects, e.g. inability to make or keep friends or to wash or eat, underachievement in school, and disciplinary problems.
A referral to a specialist may be made for a detailed assessment which includes a physical examination; tests for short-term memory, concentration and problem-solving skills; and a series of interviews or reports from parents, teachers and/or partners.
There are diagnostic criteria in children. They must :
* show symptoms continuously for at least 6 months beginning before the age of 7 (in some cases, a diagnosis can still be made if symptoms do not start until after);
* having symptoms in at least 2 different settings, e.g. at home and at school; and
* show symptoms that make social, academic or occupational lives more difficult, which are not just part of a developmental disorder or difficult phase, and are not accounted for by another condition.
There are no diagnostic criteria for adults. Currently, a diagnosis of adult ADHD cannot be made unless symptoms have been present since childhood. The symptoms cause impairment of daily activities, eg keeping friends and relationships, underachievement at work or in education, and dangerous driving.
There is no cure for ADHD. However, treatment reduces its severity and makes life less problematic. A combination of medicines and therapy is the best approach. Treatment is usually prescribed by a psychiatrist and can be monitored by the general practitioner.
The medicines include central nervous system stimulants, e.g. methylphenidate and dexamfetamine, and a selective noradrenaline uptake inhibitor, i.e. atomoxetine. The medicines provide a short period after each dose for the ADHD person to be calmer, less impulsive, concentrate better, and learn and practise new skills.
All the medicines used in treating ADHD are prescription items. The dosages will be small initially, and may then be increased gradually.
The factors considered by the doctor before prescribing include the presence of any other health conditions, its side effects, its contraindications, and whether the dosage prescribed interferes with school or work.
All 3 medicines cannot be prescribed for pregnant or lactating females. Methyphenidate cannot be prescribed for patients with glaucoma or severe depression. Dexamfetamine cannot be prescribed in patients with car-diovascular disease, eg high blood pressure or overactive thyroid (hyperthyroidism). Atomoxetine cannot be prescribed for those with glaucoma.
As is the case with most medicines, all 3 have side effects.
Regular check-ups by the doctor are necessary to assess the effectiveness of the medicine. If there is improvement, the doctor may advise a break from medicine for a short period to assess how the patient manages without the medicine.
There are different modalities of therapy.
Psychotherapy involves the patient discussing the condition and its effects. This can help the patient to cope and live with the condition.
Behaviour therapy involves managing behaviour with a system of rewards and penalties. This also provides support for parents, teachers and carers. Appropriate behaviour is rewarded with praise and encouragement, while there is a small penalty for inappropriate behaviour.
Cognitive behavioural therapy (CBT) involves the therapist trying to change how the ADHD patient feels about a circumstance, which would in turn lead to a change in behaviour. This would help increase self-esteem, reduce negative thoughts, and improve problem-solving skills.
Social skills training involve the child participating in role-play. Its objective is to teach the child how to behave socially by learning how their behaviour affects others.
Parents and caregivers can also learn management skills, eg specific ways of talking to the child and working with them to improve attention and behaviour. This also increases the parents' confidence in their ability to care for their children and their relationship with their child.
As with everyone in the population, regular exercise is beneficial for a person with ADHD.
Other treatment modalities used include omitting the consumption of certain foods and the taking of supplements. However, there is no scientific evidence that they work.
Needless to say, it would be prudent to seek medical advice prior to embarking on these modalities as they are potentially harmful if carried out in the long term.
Although there is no cure for ADHD, it can be managed with a combination of medicines and psychological, social and education therapies. Continual compliance with treatment will make life more manageable for patients, parents, carers and teachers.
More info on ADHD here.