Environmental factors like sunlight, sleep & screens may play vital roles
By Clark Powell
It’s estimated there are more than 10 million children in the United States with attention deficit hyperactivity disorder, or ADHD, and the numbers continue to rise. For decades, doctors have looked inside the minds of those patients to better understand this condition. Now in a fascinating new approach, many experts are beginning to look at external factors like the three S’s – sunlight, sleep and screens.
“This opens up new vistas for us, new things to be investigated that maybe we had not quite thought about before,” said Eugene Arnold, MD, a psychiatrist and ADHD expert at The Ohio State University Wexner Medical Center’s Nisonger Center. “It’s really quite intriguing.”
Sunlight – In a recent study published in the journal Biological Psychiatry, Arnold collaborated with Dr. Martijn Arns of the Netherlands, and found a direct correlation between the amount of sunlight children are exposed to and the rates of ADHD.
States with less sunlight have higher rates of ADHD, as much as 10 to 12 percent. “But in sunnier states, the rates of children with ADHD are cut in half, only about 5 or 6 percent,” said Arnold. The same held true internationally, with ADHD rates lower in sunny climates like Spain and Mexico.
“There are many possible explanations for that,” said Arnold. “For example, with more sunlight, maybe kids get out more to play and get more of the exercise that, increasingly, we know is good for brain function. That’s something we want to learn more about,” he said.
Sleep – Experts also want to learn more about sleep, since children with ADHD have the same traits as those who are sleep-deprived.
“There’s a correlation with things like irritability, impulsiveness and inattentiveness, which are core symptoms of ADHD,” says Arnold. “In fact, in sleep labs, you can cause this in people through sleep deprivation. You can actually get them to behave as if they have ADHD.
Interestingly, the amount of sleep children get has steadily gone down over the last two decades, while the rates of ADHD have steadily gone up. “People of all ages are getting almost an hour less sleep at night than they should be getting and we’d like to further explore that phenomenon.”
Screens – One of the most compelling reasons children are sleeping less at night is because they are increasingly exposed to screens – electronic screens – everything from computer pads to TVs to smart phones.
“These screens that are on all these electronic devices tend to emit that blue light at a critical wavelength that could be delaying the onset of melatonin,” said Arnold. Melatonin is a hormone that our bodies produce to help regulate our sleep. As the sun goes down, melatonin levels go up.
However, production of melatonin may be delayed because of exposure to electronic screens at night. More children are watching TV, playing video games or using social media on their smart phones well past sunset. “That could be having a major impact on their sleep-wake cycles,” said Arnold.
Generations of children have stayed up late, but the affects may not have been so profound. “Ordinary incandescent lights found in most homes don’t emit light at the same wavelength, so in the past, it wasn’t a huge problem,” said Arnold.
The difference may just be modern technologies and their use after dark. Incidentally, there is every reason to believe that children who live in states with more sunlight use electronic devices just as much as other children, but there is a twist.
Experts say sunlight actually overrides the blue-light effect that comes from TVs and computer screens. “They have a level of protection, it appears, that other kids don’t,” said Arnold.
Right now they are just theories, but Arnold says these external factors are worth exploring to better understand this growing problem. Arnold is currently involved in two treatment studies of ADHD and three treatment studies of autism at the Ohio State University. He has more than 40 years of experience in child psychiatric research, including the multi-site NIMH Multimodal Treatment Study of Children with ADHD.
Clark Powell is the Co-owner of Media Source, an online news service.
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