Based on a comparison of suicide rates at sea level and at areas above 2,000 feet, living at a high altitude may make people 30% more likely to commit suicide. Neuroscientist Perry Renshaw believes that it's due to the impact of altitude on the brain.
Tibetans May Be Fastest Evolutionary Adapters Ever. "A group of scientists in China, Denmark and the U.S. recently documented the fastest genetic change observed in humans. According to their findings, Tibetan adaption to high altitude might have taken just 3,000 years. That's a flash, in terms of evolutionary time, but it's one that's in dispute."