Americans and Koreans living at higher altitudes are more suicide prone, found a study published in the September issue of the American Journal of Psychiatry.
The results were based on 592,000 suicide victims in the U.S. between 1979 and 1998 and 47,000 in Korea between 2005 and 2008 analyzed by Perry F. Renshaw, at the University of Utah School of Medicine, and Kim Nam-kug, a radiology professor at Asan Medical Center, University of Ulsan College of Medicine.
Americans living at altitudes of 1,000 meters (3,281 feet) above sea level or higher were 34% more likely to commit suicide than those living below that level. For Koreans the corresponding figure was reported as 63% though the nation has no towns or cities at those altitudes. Figures were extrapolated based on an established relationship between suicide rates and altitude, said Kim.
The reason for the correlation may be hypoxia, or inadequate oxygen intake, the researchers suggested. At sea level oxygen makes up 21% of air by volume. At 1,000-meters, it drops to 18%. A prolonged state of mild hypoxia has been found to cause mild damage to the brain, which might trigger depression.
“The suicide rate is higher in the mountainous regions of northern Italy compared to the coastal south,” said Kim. “This is the first study that reveals that altitude may have a bearing on the risk of suicide.”
Yet the Korean towns known for longevity are located at altitudes of 300 to 400 meters, reports Chosun Ilbo. Among them are Gurye and Gokseong in South Jeolla Province and Soonchang in North Jeolla Province.
