Out of focus

PUBLISHED : Monday, 20 February, 2006, 12:00am
UPDATED : Monday, 20 February, 2006, 12:00am

JASON COULD NEVER focus on one activity. His mother complained that he never slowed down - not even to eat or at bedtime. He would interrupt his parents' conversations. At school, he would daydream and have arguments and fight. He always had to win every game.

Things came to a head when Jason's school called his parents with an ultimatum: either his behaviour had to change or he would be expelled. His paediatrician diagnosed attention deficit hyperactivity disorder (ADHD), then prescribed Ritalin and behaviour therapy.

Jason's parents also sought the advice of a naturopath, who prescribed a diet that eliminated sugar, wheat and food colorants. Six months on, his behaviour is under control most of the time.

ADHD is one of the most common behavioural problems in children. It affects a person's ability to regulate behaviour and attention. The main symptoms are reduced attentiveness and concentration, excessive levels of activity, distractibility and impulsiveness.

There's a wide variation in the symptoms, with some children being both inattentive and over-active, and others simply inattentive.

Some people with ADHD also have other significant mental health problems such as depression and behaviour difficulties. Eunice Wong, founder and chairman of the ADHD Foundation in Hong Kong, estimates that almost one in 10 school-age children in Hong Kong may be affected, with boys being diagnosed three times more often than girls. And it's not just a childhood problem.

'Between 50 and 70 per cent of children diagnosed with ADHD will go on to have behavioural problems as adults,' Wong says. But the causes are varied.

According to the American Academy of Paediatrics, ADHD often runs in families. Close relatives of people with the disorder have five times more chance of having it. Moreover, studies of twins and adopted children provide strong evidence for a genetic basis of ADHD.

Environmental factors also may be important, and some researchers have proposed that prenatal exposure to drugs, alcohol and cigarettes, lead and polychlorinated biphenyls (PCB) may increase the risk of children having ADHD.

It may also be related to abnormally low levels of a chemical called dopamine in areas of the brain responsible for organising thought. An abnormally low level of dopamine has been shown to worsen performance in psychological tests where the subject is required to switch between tasks and organising thoughts.

The cure is harder to ascertain. ADHD is a chronic condition and there's no short-term treatment. Instead, clinicians have to devise treatments that may include medication and behaviour therapy.

The most common treatment is Ritalin, a stimulant that increases brain dopamine activity. But, depending on symptoms, other medications such as antidepressants are sometimes used.

Medication is only part of a complete programme that requires a coordinated effort by many people, including the child, the family, school, doctors and other health-care professionals.

This approach includes parental education and training, behaviour management, an appropriate school environment, family counselling and medication.

Although dietary modification is a common alternative therapy, few large-scale studies have been conducted to test its effectiveness.

A paper in the American Journal of Diseases in Childhood, published in 1922 was the first to suggest that food could have negative effects on behaviour.

During the past century, different diets have been proposed including the Feingold diet, Few Foods Diet and the sugar- restriction diet.

Feingold Diet

During the mid-1970s, an allergist theorised that food additives, artificial flavourings, dyes and salicylates (found in aspirin, some fruits and vegetables) were causing hyperactivity and learning disabilities in many children. In his book Why Your Child is Hyperactive, Ben Feingold said that, when children were given a diet free of all these substances, half showed dramatic improvements in behaviour. When they were reintroduced back into the diet, symptoms of hyperactivity returned. Initial tests of Feingold's theory proved disappointing: only 10 per cent of children with ADHD showed the predicted allergy to food dyes and only 2 per cent on the Feingold diet showed consistent behavioural improvements when food dyes were eliminated from the diet.

Recent studies of the effects of artificial colours and preservatives on behaviour suggest that some children (not necessarily those with ADHD) may have sensitivity to specific additives and could benefit from their elimination.

Sugar-free diet

Many children have strong cravings for sugar, and some researchers say it can cause hyperactive behaviour. A review of alternative treatments for ADHD published in the Mental Retardation and Developmental Disabilities Research Reviews found inconclusive evidence to link dietary sugar with hyperactivity.

Essential Fatty Acids (EFA)

EFAs such as DHA (decosahexanoic acid), EPA (eicosapentaenoic acid), AA (arrachidonic acid) and DGLA (dihomogamma linolenic acid) play a major role in maintaining the function of nerve membranes. US scientists Fred and Alice Ottoboni proposed that major diet changes over the past century have created a significant deficiency of omega-3 fatty acids. They say the healthy development of the brain requires plenty of DHA (an omega-3 fat found mainly in cold water fish) and AA (an omega-6 fat found in meat and eggs). Growth of the brain is accelerated during the third trimester of pregnancy until the child is two. The Ottobonis say that infants whose mothers lack DHA during pregnancy or lactation or who are fed infant formulas lacking in DHA don't have the right building blocks for healthy brain development. A growing number of studies also suggests EFA deficiency is linked to hyperactivity in children.

However, a recent double-blind placebo-controlled randomised trial of fatty acid supplements showed a worsening of behavioural effects. These trials were conducted on a small number of children, so it remains to be seen.

What should you do if your child has ADHD? 'Just because certain alternative treatments haven't been shown to be effective doesn't mean that you can't try them, as long as that treatment is safe for your child,' Wong says.

'However, you should also set a limited time-frame. If the alternative treatment doesn't work, move on. Alternative therapies shouldn't be used as a replacement for demonstrated effective therapies such as stimulants and behaviour therapies. They're potentially useful adjuncts.'

For more information, go to ADHD Foundation in Hong Kong (www.adhd.hk), American Academy of Paediatrics (www. aap.org), Attention Deficit Disorder Association (www.add.org), Children and Adults with Attention Deficit/Hyperactivity Disorder (www.chadd.org)