Altitude is a Protective Factor for ADHD Diagnosis

Rates of attention deficit hyperactivity disorder (ADHD) drop as elevation increases, according to findings published in the Journal of Attention Disorders.

Researchers from the University of Utah Health Sciences retrospectively analyzed state estimates of ADHD in order to evaluate the effect of altitude on rates of ADHD. The researchers hypothesized that states at higher altitudes would have lower rates of ADHD — especially as they noted decreased dopamine activity has been linked to ADHD. Hypoxia is also linked to increased dopamine activity, they added. The researchers used the National Survey of Children’s Health report from 2007 as well as the 2010 National Survey Children with Special Health Care Needs reports for their analysis. Children aged 4 to 17 years old with diagnosed ADHD were included in the cohort.

In the 2007 report, more than 90,000 children were reached and it was determined that about 75,000 children were diagnosed with mild, moderate, or severe ADHD by a physician or other healthcare provider. The 2010 survey determined that about 40,000 children out of 372,000 households were diagnosed with full ADHD.

In the researchers’ state (Utah), ADHD prevalence was approximately 38 percent less than at sea level. The average altitude of Utah is about 4,300 feet. Average state elevations of 6,100 saw a reduced ADHD rate of about 50 percent, the researchers said.

The researchers theorize that hypoxia is involved with the reduced ADHD rates in some way. However, other inconsistencies — such as diagnosing specifics for ADHD – may also play a part.

“Our previous studies of mood disorders and suicide consistently suggest that hypobaric hypoxia associated with altitude may serve as a kind of environmental stressor,” researcher Douglas G. Kondo, MD explained in a press release. “But these results raise the question of whether, in the case of ADHD, altitude may be a protective factor.”

The state with the highest rate of diagnosed ADHD was North Carolina (15.6 percent) with an average statewide elevation of 869 feet above sea level. Other states with altitudes less than 1,000 feet, such as Delaware, Louisiana, and Alabama, followed North Carolina with the next highest percentages of ADHD prevalence.

Conversely, Nevada has an average altitude of about 5,500 feet above sea level. The state demonstrated the lowest levels of ADHD prevalence at 5.6 percent. Utah ranked among the lowest states with ADHD prevalence at 6.7 percent. The researchers added that states in the Mountains/ West range had the lowest rates of ADHD prevalence and were under the national average for children’s diagnoses.

The statement added that research has previously linked the thinner air of higher elevation to higher rates of depression and suicide, but said that reduced ADHD seems to be an added benefit of the altitude increase.