People living at higher altitudes may be at greater risk for suicide, says a new study

Living at a higher altitude may be a risk factor for suicide, a recent study in the journal High Altitude Medicine & Biology has found.

Researchers looked at suicide data in all 2,584 U.S. counties from 1979 to 1998. In that time there were 596,704 suicide deaths in 42,868,100 total deaths. Although they discovered a lower general death rate at higher altitudes, the same was not true for suicide.

An association was found between living at higher altitudes and higher county rates of suicide. The average altitude in 50 counties with the highest suicide rates was 4,684 feet, and the average altitude in 50 counties with the lowest suicide rates was 582 feet. When researchers controlled for variables such as being male, being white, and lower household income, the link between altitude and suicide was still evident.

The study authors took the Mountain Region of the U.S. (which includes Colorado) out of the equation, since that area is linked with higher suicide rates). But the association between altitude and suicide still remained.

Although the cause of the link is not known, researchers considered some theories, including the association between altitude and hypoxia (when oxygen levels in the body or a part of the body has an inadequate supply of oxygen). Other studies have shown that chronic hypoxia may worsen mood disorders. The study authors added that more research is needed to understand the reason for the relationship.

“Ultimately,” they wrote, “this mechanistic search might help clinicians to identify individuals at high altitude who may be amenable to relocation to lower altitude areas, oxygen therapy, or special monitoring and intervention.”