In 2008, Renshaw joined the Salt Lake City arm of the Mental Illness Research Education and Clinical Center. The goal of the center is to better understand and thereby reduce suicide in the population.
“Shortly after joining the center I became aware of the fact that suicide rates amongst U.S. residents are much higher in the Rocky Mountain states than in other parts of the country,” he said. “The prevailing view at that time was that this may be due to high rates of gun ownership and relative isolation of Intermountain West residents.”
Renshaw’s former job at McLean Hospital/Harvard Medical School made use of magnetic resonance spectroscopy, which studies changes in brain chemistry associated with major depression and bipolar disorder. This body of work strongly suggested that mood disorders were associated with changes in brain energy creation and utilization.
“Thus, it was not much of a leap to suggest the thin air in the high altitude states of the Intermountain West might create special problems for individuals with mood disorders,” he said. “While this idea made sense to me, many manuscript reviewers were skeptical. Our first paper was published in the Journal of Medical Hypotheses but a follow-on paper, with much more detail, was published in the American Journal of Psychiatry in 2011.”
According to the Utah Department of Health, in 2012, the most recent available reporting period, 545 Utahns committed suicide, up from 456 in 2011. In addition, Utah is the 7th highest in the nation for suicide, keeping it consistently higher than the U.S. rate. Suicide is also the fourth leading cause of death among Utahns ages 24 to 64.
Since 2010, an average 501 Utahns each year have died by suicide and another 3,968 were hospitalized or treated in emergency rooms from injuries due to suicide attempts. Kristy Jones, community projects coordinator at McKay-Dee Hospital in Ogden, said in 2012, Weber and Davis counties each lost 51 people to suicide. Weber County lost 23 per 100,000 and Davis County lost 18 per 100,000. This is the highest amount of loss in the past five years.
Renshaw, along with Dr. Doug Kondo, a Utah psychiatrist, and Rebecca Huber, a doctoral student in educational psychology, conducted a study using publicly available databases through the Centers for Disease Control as well as a high-resolution map of the altitude of the continental United States. This map was constructed by Dr. Namkug Kim, a research fellow in the U of U group.
The primary finding of the study was a strong relationship between variation in rates in suicide in the United States and altitude of residence. Similar relationships have subsequently been reported both in South Korea and in Austria.
So how does altitude affect our well being and why?
Renshaw said the prevailing view is that acute exposure to high altitudes can produce a range of medical and neurologic symptoms, including cognitive dysfunction.
“The work that we have engaged in suggests the changes in mood can appear at altitudes as low as 2000 feet above sea level,” Renshaw said. “Work in animals, by other laboratories as well as our own, suggest there are important changes in the brain neurotransmitters serotonin and dopamine associated with an increase in altitude. Low serotonin levels as we believe occurs in Intermountain West dwellers will result in increases in rates of both depression and anxiety.”
In contrast, increases in brain dopamine levels, which have also been associated with elevation, reduce the rates of attention deficit hyperactivity disorder and, more generally, give one a sense of well-being and satisfaction with essentially all the activities of daily life.
“Thus, we have what might be called a ‘Utah paradox’ whereby Utah tends to lead the nation in terms of having both the happiest and the saddest residents in the United States,” he said.
Renshaw said what to do about the problem is the focus of the group’s ongoing work.
“We are very interested in the idea that combinations of natural product supplements may well improve altitude related mood and anxiety disorders,” Renshaw said. “We are currently conducting animal studies and are trying to raise funds to conduct clinical trials.”
In the meantime, Renshaw said, most Utah residents love living in the state.
“The work that we are doing describes a much smaller number of individuals who seem to have adverse reactions to the thin air,” he said. “This likely reflects different genetic predispositions to mood and anxiety disorders. Anxiety and depression are closely intertwined, and our observations suggest that anxiety may actually be more common than depression in new residents to our state.”
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