If you’ve lived in Colorado for any length of time, you know the sun in these parts can be deleterious to the dermis.

And you’ve probably been read-in on four-bit mountain maladies like hypoxia, cerebral edema and hypobaropathy. Yet you’ve gladly accepted those risks in exchange for the wide reaches and long views available only in these rare-air regions. But before you get too comfortable, understand that science, in its never-ending quest to find new things to be upset about, has recently uncovered a new and frightening way in which our skyscraping home is trying to kill us.

The unholy alliance between altitude and suicide was first publicly noted in Utah. Frequently polling as the “happiest state” in the Union, the Beehive State also boasts the nation’s highest “depression index”, its highest use of antidepressant drugs and, most significantly, one if its highest suicide rates. A neuroscientist with the University of Utah named Perry Renshaw dubbed the disparity the “Utah Paradox” and started gathering statistics to explain it.

Renshaw’s conclusion? Residents of Orem kill themselves more often that folks in Orlando, because they’re…well…higher. Scientists in Austria and South Korea have reached similar conclusions, and after studying 2,584 counties from sea-level to shining sea-level, researchers with the Centers for Disease Control (CDC) cautiously concur.

“Altitude is strongly associated with suicide rates,” reads their 2011 abstract. “This novel finding is not explained by county differences in demographic factors, income, or geographic isolation.”

That qualifier was welcomed with poor grace by a chorus of gun-control advocates, sociologists and mental health professionals that had immediately ascribed Renshaw’s discovery to various other factors peculiar to the Mountain West, such as a greater incidence of gun ownership, more remote living circumstances and less access to mental health services. In fact, the CDC considered all of those variables, and more, before reaching the guarded conclusion that altitude matters.

If you graph suicide rates on a map, what emerges is a broad band of self-destruction centered squarely on the Rocky Mountain corridor and bleeding west into the Great Basin. A CDC report for 2012 sets the national suicide rate at 12.6 per 100,000. Listed in descending order of auto-mortality, the most suicide-prone states in the nation that year were Wyoming (29.6), Alaska (23.0), Montana (22.6), New Mexico (21.3), Utah (21.0), Colorado (19.7), Idaho (19.7), Nevada (18.2), Oregon (18.0) and Oklahoma (17.8). 

On the brighter end of the scale, states with lowest suicide rates also tend to be lower-slung. Witness Rhode Island at 9.5, Massachusetts at 8.7, New York at 8.3, New Jersey at 7.4, and, curiously enough, Washington, D.C. at 5.7, the lowest rate in the nation.

No matter how you crunch them, the numbers lean to the lofty, although Renshaw insists the phenomenon is discernible at elevations as low as 2,000 feet. And if Alaska’s unfortunate second-place showing seems a bit anomalous, consider that while most of the Last Frontier isn’t all that high, it tends to be dark, and that’s not good for anybody’s head.

Closer to home, the tragic association between altitude and suicide is even easier to follow. The great mass of precipitous playgrounds that are Gilpin, Clear Creek, Park, Lake, Teller, Chaffee, Fremont and Custer counties routinely surpass the state average in suicides, while the counties of the plains – particularly the northeastern plains – consistently come in well below it. In 2010, upland and upscale Pitkin County, with a mean elevation of 9,940 feet, posted the sad toll of about 35 suicides per 100,000, the worst in the state by a solid margin. Down-to-earth Otero County, at a more modest 4,500 feet above the sea, was relieved to report a rate of just 14.9 during the same period. For what it’s worth, middle-class and middle-of-the-road Jeffco neatly split the difference with an average elevation of 7,055 feet and a suicide rate of just over 18 lost per 100,000 souls.

But quoting statistics is easy. Explaining them not so much. How do the thinking classes account for the fact that Intermountain West dwellers are up to 30 percent more likely to kill themselves on purpose than their down-slope countrymen? According to Renshaw, it’s a mental problem.

Protracted exposure to the relatively low oxygen levels at high altitudes appears to affect serotonin and dopamine levels in the brain. Serotonin and dopamine are the two chemicals most responsible for telling your brain to feel happy. Serotonin helps stabilize the emotions, while dopamine helps focus the mind. Women, in particular, are at risk of altitude-related mood disorders, since they generally run on about half as much serotonin as men. Exactly how altitude unbalances those essential ingredients of a contented bean is not known, but it’s hard to question the results.

To pick one example, a 2005 study by the Naval Health Research Center evaluated a group of Marines before and after they left their San Diego base for a month of intensive physical training in the Sierras. The soldiers returned physically more fit, but in mental and emotional shambles. Not only were they far more irritable, moody, anxious and distracted than when they left, in almost every case those symptoms persisted for at least 90 days.

To pick another, a surprisingly high percentage of new instructors at the United State Air Force Academy in Colorado Springs bug out after just a few months, typically citing depression and an inability to concentrate. What’s more, cadets hailing from higher altitudes consistently out-perform their lowland-bred classmates. In both cases, the unhappiness and loss of mental acuity can neatly be explained by altitude-adjusted serotonin and dopamine levels. But is it enough to turn thoughts to suicide?

Renshaw proposes that while most people can shrug off a moderate serotonin/dopamine tweak, it’s likely that some people, especially those suffering from severe stress, depression, anxiety or some other pre-existing mental ailment, simply can’t. Thin air can be the five of clubs that brings down the whole house of cards. On the other hand, altitude isn’t apt to push anybody over the cliff unless they’re already standing on the edge.

Not surprisingly, there may soon be a pill for that. Top American chemists are even now laboring to develop an all-natural dietary supplement they claim will ease the effects of high-elevation respiration. Curiously enough, if you’re reading this you may never need it, because there’s one more paradox that bears mention.

In grilling countless subjects, Renshaw noticed a pronounced tendency in people transplanted from low altitude to high altitude to spend a lot of time moaning about the mountains and pining for their sea-level roots. Just as often, however, former Intermountain West residents who’d suffered geographical demotion described feeling fatigued and scatter-brained and urgently drawn by “the call of the mountains.” A significant percentage, in fact, only escaped those persistent symptoms by fleeing back to their erstwhile aeries.

Sure, that could be sentimentality in action, a purely psychosomatic response, but it could also represent a genuine physiological adaptation to the rigors of thin air. As Renshaw explains, oxygen-poor air typically increases the brain’s dopamine levels, much as a margarita, a Valium or fat spliff would. What those innocents abroad may have been missing is, quite literally, a Rocky Mountain high.