The likelihood of your child having attention-deficit/hyperactivity disorder (ADHD) depends, at least in part, on where you live. A new analysis from the University of Utah finds that the rate of ADHD decreases as altitude increases. That is, the higher up you live, the less likely you are to have ADHD. The findings suggest that dopamine may play a central role in protecting the brain against ADHD. The results may also have implications for the treatment of ADHD.
The researchers drew data from two national health surveys. The National Survey on Children’s Health contacted nearly 92,000 households with children aged 4 to 17 in 2007. They found over 73,000 children diagnosed with ADHD by a health care provider. The 2010 National Survey of Children with Special Healthcare Needs contacted nearly 373,000 households with children aged 4 to 17 and found over 40,000 children diagnosed with ADHD. The researchers of the present study correlated the data from these surveys with information from NASA on the average elevations of 48 states and the District of Columbia (Hawai’i and Alaska were excluded). They accounted for factors like birth weight, ethnicity, and sex in their analysis.
Higher altitudes were correlated to lower levels of ADHD. For every one-foot increase in elevation, there was a .001 percent decrease in the likelihood of being diagnosed with ADHD. North Carolina, the state with the lowest average elevation had the highest prevalence of children diagnosed with ADHD at 15.6 percent. In contrast, Nevada, the state with the highest elevation, had the lowest prevalence of ADHD at 5.6 percent.
The explanation for this phenomenon may lie with dopamine production. Higher elevations mean decreased oxygen levels, which result in a condition called hypobaric hypoxia. One of the results of hypobaric hypoxia is increased dopamine production. Other studies have found that decreased dopamine levels are associated with ADHD.
The findings have implications for ADHD treatment. Many ADHD medications increase dopamine. It is possible that higher dopamine levels—from medication or other environmental factors—could aid the treatment of ADHD.
This research is published in the Journal of Attention Disorders.
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