Is it possible that living in the mountains can make it more likely that someone will commit suicide? Maybe, according to startling new research suggesting that for someone who already has mental health problems, thinner air may be one factor leading to self destruction.
That finding may seem a bit baffling at first blush, but psychiatrist Perry F. Renshaw of the University of Utah said his team of researchers have found an "astonishingly strong" correlation between living at higher altitudes and the suicide rates across the country. The data had been collected by various agencies between 1979 and 1998.
"We mapped the altitude of all of the counties in the United States and looked at suicide rates over that 20-year period and the association was extraordinarily strong statistically," Renshaw said in a telephone interview.
The data may help explain why the Rocky Mountain states and others with high elevations in the western part of the country consistently report the highest rates of suicide per 100,000 persons. Alaska, Montana, New Mexico, Colorado, Utah and Nevada rank in the top 10 suicide states year after year after year.
Renshaw, senior author of a study just published in the American Journal of Psychiatry and a specialist in brain imaging, offered one possible explanation for why thin air may contribute to higher suicide rates.
"I worked on the east coast for many years, studying brain chemical changes associated with depression," he said.
Depression has been linked to suicide in at least 60 percent of the cases, he added, so he was intrigued when he detected chemical changes in the brains of depressed people that had an effect on metabolism, the sum of the physiological processes that make it possible for an organism to grow new cells and tissues, and generate the energy necessary to maintain life.
Renshaw's working hypothesis is that thin air contributes to mild hypoxia, metabolic stress caused by inadequate levels of oxygen, which may in turn aggravate existing mental health problems. So there's no suggestion here that moving to the mountains may cause a mentally healthy person to commit suicide, but he believes that in some cases it may be a significant risk factor.
Suicide is an extremely complex phenomenon, he noted, and there are many other factors. Availability of firearms, which are used in most suicides, and drug and alcohol abuse, as well as overall mental health, are certainly leading causes. But he thinks his team has found a new contributor.
Only one other team, at Case Western Reserve University, has found a link between elevation and suicide, but their complete work has not yet been published. So this is "uncharted territory," as Renshaw put it.
Renshaw's team has repeated its findings in two other mountainous countries, Italy and South Korea. The lead author of the study, Namkug Kim, is from South Korea and had access to data banks there.
"South Korea has a very high suicide rate, first or second highest in the world, and South Korea has a tremendous range in altitude from sea level up to several thousand meters," Renshaw said. "We found the same thing there. The higher the altitude, the higher the suicide rate."
The Utah study began a couple of years ago when Renshaw heard a talk by a suicide specialist who presented maps of suicide rates in the United States.