Led by Dr. Brent Michael Kious, scientists from the University of Utah have come to the conclusion that people living at higher altitudes may have an increased risk of suicide. The researchers do have a theory as to why this might be the case, along with some recommendations.

Kious and colleagues analyzed 12 previous studies (most of which were conducted in the US) that looked at the relationship between suicide or depression and altitude. What they found was that on a per-capita basis, suicides were more prevalent in the intermountain states of Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah and Wyoming – although Alaska and Virginia also had high rates.

When the scientists adjusted US suicide rates for population distribution, suicides per 100,000 people were 17.7 at high-altitude locations, 11.9 at middle altitudes, and just 4.8 at low altitudes. Instead of there being a steady increase with altitude, however, the rates jumped dramatically at altitudes between approximately 2,000 and 3,000 feet (610 and 914 m).

While the studies couldn't account for all other factors that might lead to higher suicide rates in certain places, things such as increased poverty and lower income were also found to play a part. Interestingly, however, the populations living at higher altitudes had a lower risk of death from all causes combined. Additionally, the rate of firearm ownership was found to be less of a factor than altitude.

According to Kious' team, the reason for the increase in suicide rates with altitude may be what's known as chronic hypobaric hypoxia – low blood oxygen levels caused by low atmospheric pressure. The researchers believe that this could conceivably be addressed by using medication to either increase levels of the neurotransmitter serotonin, or "to influence brain bioenergetics."

A paper on the research was recently published in the Harvard Review of Psychiatry.