New research has identified a surprising benefit to living at high elevations: The prevalence of attention deficit hyperactivity disorder appears to decline substantially as elevation increases.

In a study published in the Journal of Attention Disorders, University of Utah researchers found residents of Nevada — average elevation: 5,517 feet above sea level — have the lowest percentage of ADHD cases of any state, with 5.6 percent of children diagnosed with the condition, Live Science reports.

What’s more, all of the states in the Mountain West region have ADHD rates well below the 2007 national average rate of 9.5 percent.

A possible explanation: People who live at high elevations breathe air that has less oxygen, which boosts levels of the brain chemical dopamine which in turn lowers the risk for ADHD.

"To treat ADHD, we very often give someone medication that increases dopamine," said researcher Perry F. Renshaw, M.D. a professor of psychiatry at the University of Utah. Renshaw said.

But he said the new study suggests parents and children with ADHD, and their physicians, should consider the effects of higher elevations. For example, a family vacation in the mountains could be timed to coincide with a period without medication — what doctors call a stimulant holiday.

"That might be better for everybody," he said.

To reach their conclusions, the researchers analyzed two national health surveys — tracking more than 370,000 families, including children diagnosed with ADHD — and compared that cross-referenced it with formation about the average elevation of each state.