As a result, scientists are now trying to discover how brain chemistry may be affected by higher elevation, where there is less oxygen than at lower elevations. More research is necessary, and Renshaw would like epidemiologists to examine the issue. One question is whether people with some mental illnesses such as depression could be at increased risk of suicide by residing at higher altitude.
"The goal is not to say, 'This is terrible, everyone in Utah should move to sea level,' " said Renshaw, who is an investigator with the Utah Science Technology and Research (USTAR) initiative. "If you can find risk factors that are important, you can try and address them."
Many of the Intermountain West states have some of the highest suicide rates in the country. As of 2007, the most recent year national information was available from the CDC, Utah had the ninth-highest suicide rate in the nation. Alaska was No. 1.
More-up-to-date data from the Utah Violent Death Reporting System indicates the suicide rate increased 12.7 percent between 2008 and 2009 after remaining fairly steady during the past few years. The state Medical Examiner's Office has also observed a high number of suicides in Utah so far in 2010.
The new research indicated that actual elevation increased suicide risk. For example, the risk was nearly one-third higher at approximately 6,500 feet. Past research has confirmed the connection between higher altitude's decreased oxygen and "worsening" mood potentially lasting for several months.
Another of the report's authors, Namkug Kim, did a similar study of South Korean data in which the suicide rate increased by 125 percent at about 6,500 feet.
"Always the question that families have is why," said Sherri Wittwer, the executive director of the National Alliance on Mental Illness in Utah. "Any information we can get to lend some answers is always helpful, but mostly so we can use that information to help prevent suicide in the future."
But for some experts, this research doesn't definitively answer the question as to why the Intermountain West's suicide rate is so high.
A closer look at other variables could illuminate what else is common in the region, said Lanny Berman, the executive director of the American Association of Suicidology.
"This may have nothing to do with altitude," he said, noting mental health resources and the economy are among the other factors that could play a role.
Are you in crisis?
To find help for yourself or someone you know 24 hours a day, call 1-800-273-TALK (8255). More information about suicide prevention can be found online. > suicidepreventionlifeline.org.