A disorder depends on the eon

The symptoms of attention deficit disorder arguably might have been an advantage in post-nomadic societies. That could explain why the mutated gene behind it was so successful.

For hunters and others in the second Ice Age, above, symptoms of what we consider Attention Deficit Hyperactivity Disorder could have been an advantage.

At about the same time as early humans began planting crops and creating permanent settlements, the gene linked to dopamine reception in the brain began to mutate. One of the various mutations that developed, scientists have found, is one that is linked strongly to both ADHD (attention deficit hyperactivity disorder) and a behaviour trait known as "novelty seeking", which frequently underlies addiction.

ADHD entails acute inattention and in children, at least, behaviour that is not conducive to a traditional educational environment or, frequently, to a peaceful home life. Between three and five per cent of the world's population are believed to have the condition. Dr Raymond Hamden, a clinical and forensic psychologist with the Human Relations Institute in Dubai, said the behavioural disorders associated with ADHD fall into three categories: hyperactivity, short attention span and impulsive behaviour.

"This is usually related to a chemical imbalance," said Dr Hamden. For all the negatives that contemporary society attributes to the above behavioural disorders, there are very strong indications that the presence of the mutated gene, known as DRD4/7R, plays a very positive role in some societies. A study conducted at Northwestern University in Illinois found that ADHD actually can be an advantage to children and adults who live in nomadic, tribal societies. Adults from the Ariaal tribe of Kenya who have the DRD4 gene and its mutated tick of an allele, the 7R, were better nourished than their more docile counterparts.

"The DRD4/7R allele has been linked to greater food and drug cravings, novelty-seeking and ADHD symptoms," wrote Dan Eisenberg, one of the authors of the study. "It is possible that in the nomadic setting, a boy with this allele might be able to more effectively defend livestock against raiders or locate food and water sources." Yet, in a more sedentary society, such behaviour stemming from what we term a "disorder" can result in all kinds of problems for the carrier.

"The same tendencies might not be as beneficial in settled pursuits such as focusing in school, farming or selling goods," Eisenberg wrote. Dr Hamden believes that dopamine-related drugs such as Ritalin are often prescribed by people who don't know how to diagnose ADHD and related symptoms. "It's a professional crime," he said. "ADHD can be taken care of with proper dieting. Some of these kids actually have allergies to sugars, caffeine and preservatives. What we found in our practice was that when kids were put on a proper diet and given a behaviour chart and a time-out programme, 70 per cent of them did not require medication."

Ritalin, which Dr Hamden considers a safe drug when used properly, is restricted in the UAE, and many parents with children who suffer from ADHD have complained about a lack of space in mainstream and special needs schools. The effects on society of the mutated DRD4 have been felt for tens of thousands of years. A study done at the University of California at Irvine found that the offshoot probably developed between 10,000 and 40,000 years ago. This was the time when humans were starting to form social hierarchies and develop complex technologies and more sophisticated agricultural practices. Humans were learning to adapt to new landscapes and different climates and breeding in greater numbers. The California study suggests that there was a preponderance of the mutated gene at this time and that it was not a coincidence.

The human notion of novelty seeking and the need to seek out new land, life and livestock were part and parcel of developing societies, all of which may have contributed to the success of the gene. Its solid success then would account for its prevalence in modern gene pools. Today's society, however, puts different demands on its members. A research paper published by Harvard Medical School this year advised workplaces to screen their employees for ADHD after finding that adults with the disorder performed about a month's worth less work in a year than did their co-workers.

"We are living in an era in which the physical prowess and mental ambition needed in the everyday scope of life are much less than even 100 years ago, when constant robust work was required from morning until night," Dr Hamden said. "Then many people didn't finish elementary school because they had to work on the farm." Modern schools, he said, are designed for the majority. Although children with attention deficit disorders have trouble learning and organising themselves, they are often highly creative individuals who require an alternative educational approach, Dr Hamden said.

Certainly, classifying people with ADHD as "handicapped" can cause not only undue harm to those with the condition but, in the long run, can render untold damage to the evolution of society itself. Nowhere is that more evident than in an anecdote about Gillian Lynne related by Sir Ken Robinson, an education specialist, at a recent symposium in California. "When she was in school in the 1930s she was really hopeless," Robinson began. "Her school wrote to her parents and said she had a learning disorder. She couldn't concentrate. She was fidgeting. I think now they would say she had ADHD. But this was the 1930s and ADHD hadn't been invented. It wasn't an available condition."

Ms Lynn was brought to a specialist who spent 20 minutes discussing her school-related problems as the young girl sat on her hands and squirmed. At the end of their conversation, he turned on the radio and left the room. Immediately, Gillian stood up and began to move. "The specialist turned to her mother and said 'Mrs Lynn, Gillian isn't sick, she's a dancer'." Years later, Ms Lynn became a soloist at the Royal Ballet School. Later still, she became the world-famous choreographer behind the Broadway musicals Cats and The Phantom of the Opera.

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