SALT LAKE CITY — Living the Rocky Mountain high life could increase the risk of people feeling desperately low, new data indicates.
Research from an investigator with the University of Utah Brain Institute showed the Intermountain West's high altitude has a significant influence on the high prevalence of suicides in this part of the country.
The findings will be published in today's Wednesday's online edition of the American Journal of Psychiatry.
A group of researchers led by Dr. Perry Renshaw, professor of psychiatry at the University of Utah School of Medicine and an investigator with Utah Science Technology and Research initiative, reports that the risk for suicide increases by nearly one-third at an altitude of 2,000 meters, or approximately 6,500 feet above sea level.
"Suicide is a rare event, and it tends to happen in some groups of individuals more than others," he told the Deseret News.
The Western states, including the Intermountain West, have some of the highest average elevations in the nation, according to data from the National Geospatial Intelligence Agency and the National Aeronautics and Space Administration — and the highest suicide rates.
In 2006, the latest year for which national data was available, Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah and Wyoming accounted for nine of the 10 highest suicide rates in the nation. Alaska was also among the top 10.
Utah's suicide rate was 10th highest in 2006, while Nevada had the country's highest rate.
The Beehive State's suicide rate was about 50 percent higher than the national average, said Renshaw, the study's senior author.
"We're talking ... on an annual basis of 150 extra suicide deaths every year," he said. "There is something about the thinner air that changes our brain chemistry."
The high suicide rates in the West prompted Renshaw to undertake the research, with the hope of locating a cause and developing a way to combat this tragic problem.
"We thought it was reasonable to ask if some aspect of high altitude is related to suicide," he said. "Altitude was the strongest factor we could find in our study."
But the researchers believe there is also some other factor they can't account for yet, Renshaw added.
After analyzing data from a U.S. Centers for Disease Control and Prevention on each of the 3,108 counties in the lower 48 states and District of Columbia, Renshaw and his colleagues concluded that altitude is an independent risk factor for suicide and that the association may have arisen from the effects of metabolic stress associated with mild hypoxia (inadequate oxygen intake) in people with mood disorders.
In other words, people with problems such as depression might be at greater risk for suicide if they live at higher altitudes.
The researchers also concluded that the West's higher rates of gun ownership, a well-recognized factor in suicide, and lower population density — suicide is more prevalent in rural areas — may also be connected with altitude influencing suicide rates.
"These findings provide a new and important area of investigation for understanding suicide risk," said Deborah Yurgelun-Todd, a USTAR investigator and University of Utah professor of psychiatry.
According to the study, Utah has the third highest average altitude in the country — 1,940 meters (6,364 feet) above sea level — and had a rate of 14.1 suicides per 100,000 people in 2006. New data from the Utah Violent Death Reporting System shows suicides in the state are on the rise, increasing nearly 13 percent from 2008 to 2009.
Colorado has the nation's highest average elevation at 2,200 meters (approximately 7,217 feet) above sea level. It had 15.8 suicides per 100,000 people over the period, the seventh highest rate. Nevada was the highest, at 19.6 per 100,000 people.
To verify the study's conclusions, data was studied in South Korea, where researchers found that the suicide rate in areas at 2,000 meters (about 6,550 feet) increased by 125 percent. Additional study is to be conducted in China and high-elevation South American countries as well, Renshaw noted.
Understanding the full relationship between altitude and suicide will require much more study, he said.
"If altitude is related to suicide, then perhaps we could look with greater urgency at why this is true and what we can do to prevent it," Renshaw said.
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