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US News (below) provides compelling reasons NOT TO DRUG children diagnosed with ADHD. It seems scientists are beginning to recognize the positive aspects of restlessness and impulsive behavior.
Paul Schurke, a 46 year old polar explorer and dogsled trekking company owner, for example, notes that lucky for him in the 1960s when he grew up, no one heard of ADHD, so he was free to pursue his lust for adventure. He says restlessness and impulsiveness the “classic signs” of ADHD were definitely an advantage for him.
The article presents an interesting speculation leading some scientists to suggest that those with a genetic variant of the gene DRD4— don’t need medication! Researchers found that “there are hints that people who have the 7R form of DRD4 might be more active, more likely to take risks, and hungrier for new experiences than people with other versions of the gene.”
Thus, the article notes that Schurke still bites his nails, talks quickly, and says he has “a nervous buzz going all the time.” He doesn’t know or care if he has 7R, although he is grateful for whatever is the source of his boundless energy.”
Why are children today not entitled to the same freedom to explore their own calling?
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As a child, Paul Schurke showed all the classic signs of attention deficit hyperactivity disorder. He fidgeted at school. He rode his bicycle through underground construction zones. On impulse at age 14, he and a friend took a canoe into the Wisconsin wilderness, where they plunged over waterfalls until they cracked the boat in half. But when he was growing up in Minneapolis in the 1960s, no one knew about ADHD, Schurke says, and he never considered that there might be something wrong with him.
Instead, he found ways to use his restlessness to his advantage. He took part in a record-setting dogsled expedition to the North Pole in 1986. He later started his own dogsled trekking company, wrote two books, and won several awards for his adventures. Now 46 and still unable to sit still, Schurke says ADHD-like behaviors are an asset in his line of work. “By all acts I was blessed with a great curiosity that has driven me for the rest of my life,” he says. “It’s a common trait among all of us in the adventure world.”
To be sure, ADHD causes a great deal of suffering for millions of kids and adults, who are so easily distracted, impulsive, or hyperactive that it can be hard to simply get through a day at school or work. Yet scientists are starting to think, like Schurke, that at least some attention deficit “disorders” have a positive side which might have been more apparent early in human history, before classrooms and play groups. Researchers have zeroed in on a single gene variant that appears linked to many cases of ADHD, and they have tracked it around the globe, uncovering hints that it may have supplied a restless urge that drove our ancestors to explore the planet.
Solid link. The gene in question, called DRD4, is one of five coding for “receptor” proteins that allow brain cells to pick up a chemical messenger called dopamine, which influences motivation and behavior. DRD4 is one of the most variable genes in the human body, perhaps accounting for some of the ways people differ in behavior or personality. Among its 11 forms, one the so-called 7-repeat variation, or 7Rˆappears in about half of kids with ADHD but just 20 percent of those without the disorder. “This is the most highly replicated and therefore most solid finding linking any gene to any behavior or behavioral disorder,” says University of Toronto psychiatrist James Kennedy, who a decade ago was one of the first researchers to study DRD4.
How the gene might contribute to ADHD is not certain, but there are hints that people who have the 7R form of DRD4 might be more active, more likely to take risks, and hungrier for new experiences than people with other versions of the gene. One is a study, published in 2000 in the Proceedings of the National Academy of Sciences, that found kids with 7R were more likely to get up from their desks and shove other kids around, Kennedy says. “My favorite word at the moment is restlessness,” he says. “People tend to move around more if they have the 7-repeat allele.”
That same genetically inspired impulse to move around could help explain migrations of entire populations, says biochemist Robert Moyzis of the University of California-Irvine. Based on clues from the DNA sequence in and around the 7R gene, he estimates that the original mutation dates to about 40,000 years ago. That was a crucial moment in human history, Moyzis says. “That’s exactly the time when there were major explorations of Earth going on by human beings.” It’s easy to imagine how natural selection could favor a mutation like 7R among migrating people, Moyzis says. “Maybe people who were out running around doing the exploring were doing a better job bringing home the bison.”
Indeed, 7R seems to be most common in cultures with a history of migration. In South America, where the first settlers traveled enormous distances from Asia beginning over 12,000 years ago, more than 60 percent of the native population has 7R, studies show. But in parts of Asia where the current populations have historically been fairly sedentary, less than 1 percent of the people have it. A 1999 study by UC-Irvine psychologist Chuansheng Chen and colleagues also found that 7R is more common in Jews whose ancestors migrated long distances from the Middle East, to Rome and Germany, than in those whose ancestors stayed closer to home. “The facts are pretty clear,” Chen says, “that the DRD4 gene has experienced positive selection.”
Not all experts agree. “All too often, people who look at only one gene and see frequency differences between populations assume selection must be the explanation,” says geneticist Kenneth Kidd of Yale University. “In fact, that is the norm.” Still, Chen and others point to evidence that kids with 7R react faster to new challenges, an effect evolution might have favored. In one study, Chen and colleagues at UC-Irvine instructed children to draw a 14-part alien on a blank sheet of paper. After four minutes, children with 7R had done a better job of focusing on instructions and had drawn more complete aliens than other children, the researchers found.
Career changes. What these tantalizing clues might mean for kids with ADHD today isn’t clear. Perhaps those with the 7R variant of the gene don’t need medication, just a different career track as explorers, for example, or entrepreneurs. But kids aren’t tested for 7Rˆand they won’t be until researchers have a better understanding of the gene. “There is a crying need to figure out what the gene actually does,” says anthropologist Henry Harpending of the University of Utah in Salt Lake City.
Polar explorer Schurke still bites his nails, talks quickly, and says he has “a nervous buzz going all the time.” He doesn’t know or care if he has 7R, although he is grateful for whatever is the source of his boundless energy. But, he adds, “It would be interesting to see what my mother thinks.”
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