There are many known risk factors associated with suicide: those who take their own lives are statistically more likely to be white, male, and/or low-income. Surveys show that they are also more likely to have histories of depression, own fire arms and feel isolated. Many are divorced or have substance abuse problems. But a team of researchers found another risk factor that is less intuitive, even though it may be just as valid: living at a high altitude.

外国研究者通过大量事实发现：致人萌发“寻短见”念头的因素众多，轻生者中又以低收入的白人男性为主，调查发现，这类人通常有抑郁症病史，有过犯罪经历和深感孤立无援。另外许多则是因为离婚和药物滥用等问题，但最近，有一个研究组则发现了另一个不明显而影响力有限的诱因——所处的海拔高度。

The team, lead by Dr. Barry Brenner from the University Hospitals Case Medical Center in Cleveland Ohio, analyzed 19 years worth of cause-of-death data from all 2,584 U.S. counties (between 1979 and 1998). In their study, published in High Altitude Medicine & Biology, they compared the 50 counties with the highest suicide rate to the 50 counties with the lowest, and found that county altitude was on average almost eight times higher in the areas with high suicide rates.

该小组研究了全美2584个县在1979年到1998年间的十九年中导致自杀事件的所有数据，他们将发生率最高的50个县与最低的50个县惊醒对比，发现海拔相较于平均值高出八倍的地区的自杀率也会相应的升高。

Even when the researchers controlled for five other suicide-related factors — two measures of income,race, age and population density of the county — the correlation was still strong. Wrote the scientists:

同时，这项调差还将另外五了因素列为了诱因，其中两项与收入有关，此外，种族，年龄，以及密集程度，这些因素都具有强烈的相关性。科学家们说：

Prior reports of increased suicides in the U.S. Mountain Region (e.g., Colorado) have prompted speculation that the excess is owing to greater access to rearms, increased isolation, or reduced income. Even after controlling for these variables in our analysis, the positive correlation between altitude and suicide still exists, which suggests that the increased suicide rate in the regions with greatest altitude, such as the Mountain Region, may be owing to, at least in part, its altitude per se.

之前的报告中所称的美国山地地区(例如科罗拉多州)的自杀率的上升与该地区枪支泛滥、隔离程度的提高以及收入的减少都可能存在着联系。然而在这些数据进行归纳分析后，我们发现，所处的海拔高度与自杀事件之间也有关联，这表明了在诸如山区这样的高海拔地区的自杀率的上升的原因中，至少有一部本是因自身所处的环境(海拔)所致。

The authors note that there may be physiological reasons why high altitude may contribute to suicides; low barometric pressure in mountainous regions, for example, causes the body to become less efficient in transporting oxygen from the air, and these changes can affect brain functioning. In addition, they note, it’s only suicides, and not other deaths that are positively associated with higher altitudes. While the results still need to be replicated, they at least suggest that achieving the "mountain high" may come at a dangerous price.

文章的作者还指出，有很多生理上的因素也说明了为何在高海拔地区会出现较高的“轻生”率，这些地区的大气气压较低，由此导致了人体输送氧气的效率较低，这将影响到大脑功能。此外，除了自杀以外的其他死亡现象也和这一地理因素有关。尽管对于这项研究所提出的说法还有待检验，但它至少给我们提了个醒，人在“高处”不但不胜寒，或还不“安全”。