by Subjectivist » Tue 18 Nov 2014, 08:04:13
A new study of suicide in America has come out that makes interesting reading. It seems that people who move from one altitude regime to another go through an adaptation in brain chemistry because of the persistent change in the partial pressure of oxygen they are breathing. A person who grows up at sea level who moves to Denver, CO the mile high city, has a 30 percent higher suicide rate than a person born and raised at similer altitude.
By the same token the USAF academy in Colorado Springs, CO has a hard time recruiting and keeping faculty from lowland area's because they frequently express a difficulty concentrating.
For those planning to bug out to a mountain retreat to avoid global warming or zombie hords, you better try high altitude first and see if it adversely effects you personally.
$this->bbcode_second_pass_quote('', 'T')his partner story is part of BrainMic, a collaboration with GE to share the latest advances in brain research and technology.
Living in Utah means packed powder in April, canyoneering in the clouds, snow-capped vistas so vivid they look Photoshopped — and the shortest average work week in the country. So it's not surprising that surveys show how much Utah residents love their outdoorsy, adventure-filled state.
But there's another side to Utah that isn't shown in surveys. Despite ranking as America's happiest state, Utah has disproportionately high rates of suicide and associated mood disorders compared to the rest of the country. In fact, it's the No. 1 state for antidepressant use. These polarized feelings of despondency and delight underlie a confusing phenomenon that Perry Renshaw, a neuroscientist at the University of Utah investigating the strange juxtaposition, calls the "Utah paradox."
Utah residents and experts are aware of the paradox, often attributing gun use, low population density and the area's heavy Mormon influence as potential factors. But Renshaw thinks he's identified a more likely cause for the Utah blues: altitude.
Renshaw believes that altitude has an impact on our brain chemistry, specifically that it changes the levels of serotonin and dopamine, two key chemicals in the brain that help regulate our feelings of happiness. America's favorite antidepressants (and party drugs) work by controlling the level of these chemicals in the brain. The air in Utah, one could say, works just like this.
Since moving to Utah in 2008, Renshaw has found mounting statistical, scientific and anecdotal support for his theory. If Renshaw's theory holds true, his work represents a major step forward in solving a long-standing mental health mystery.
Westward, ho?
Utah lies in a region of the country commonly known as the Rockies, the mountain states or even just "out west." To those who analyze violent death data, it's known as the "suicide belt."
According to the National Violent Death Reporting System, a surveillance system run by the Centers for Disease Control and Prevention, Utah and other states in the Rockies consistently have the highest suicide rates in the country aside from Alaska. In the map below, the block of red — states with suicide rates over 14 per 100,000 people — is hard to miss.
Before heading west, Renshaw studied the effects of drug abuse on brain chemistry at Harvard Medical School. When he started working at the Salt Lake City Veteran Affairs' mental illness center five years ago, suicide research was a priority. Shortly after Renshaw arrived, a suicidologist presented a map depicting suicide rates.
"From the beginning," Renshaw said, recalling his developing eureka moment, "the statistical evidence seemed off the charts."
To see if statistics could help explain why so many mountain-dwelling Americans commit suicide, Renshaw analyzed data on altitude, suicide and mental illness over the last five years.
In a 2011 study published in the American Journal of Psychiatry, a group of researchers, including Renshaw, analyzed state suicide rates with respect to gun ownership, population density, poverty, health insurance quality and availability of psychiatric care. Of all the factors, altitude had the strongest link to suicide — even the group of states with the least available psychiatric care had fewer suicides than the highest-altitude states, where psychiatric care was easier to find.
In a follow-up study, Renshaw looked at instances of suicide that involved guns and those that didn't. Again, he found a positive correlation between suicide and altitude across the board.
Renshaw also used CDC violent death data to examine the relationship between altitude and mental illness. The elevation at which people live, he found, is a strong predictor of their mental health status.
Renshaw discovered research supporting his theory. Doctors from Case Western University, it turned out, were crunching numbers based on a similar hunch about altitude and suicide. In a 2010 study published in High Altitude Medicine and Biology, the Case Western group analyzed suicide rates across 2,584 counties in 16 states and found that suicides start increasing between 2,000 and 3,000 feet in all U.S. regions. The U.S. isn't a special case — analysis of suicide rates in other countries, including South Korea and Austria, bore similar results.
Psychology research has also made a connection between mental health and elevation. In a 2005 study, the Naval Health Research Center measured mood changes in Marines who left seaside San Diego for 30 days of strenuous training in the Northern California mountains. Before training, the Marines completed a self-evaluation of their levels of anxiety, dejection, fatigue and bewilderment, among other mood symptoms. They completed the same evaluation after training ended, and then again 90 days later. While their physical fitness improved during training, their mental health disintegrated. Before training, the Marines reported more balanced mood levels than average college-aged men. By the time they finished, they described mood symptoms comparable to those of psychiatric patients. Ninety days later, they were just as sad and agitated.
All of this evidence, Renshaw says, seemed too strong to dismiss as coincidental. 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.
In addition to the statistical evidence, Renshaw collected anecdotes that supported his developing theory.
Five years ago in Park City, Utah, Renshaw presented his theory and his research on suicide. Afterward, he was approached by a female audience member who was part of a support group of women — women who began showing symptoms of anxiety and depression only after they moved to Utah. She was floored to hear Renshaw's theory, which made sense of her group's shared, confusing mental health issues.
And Renshaw also learned that the U.S. Air Force Academy in Colorado Springs, Colorado, which sits 7,000 feet above sea level, struggled to hold on to out-of-state professors, who often left after a few months because they felt off, physically and mentally. Out-of-state students from low-altitude areas also fared worse academically than their in-state counterparts.
Renshaw himself undertook an informal study of researchers who moved to Utah from coastal areas and found that around 35% experienced new, often pronounced, symptoms of anxiety and depression.
Still, a host of evidence spoke to the other side of the paradox — the positive feelings associated with living in America's "happiest" state. Clinical trial participants who grew up in Utah and moved away, for example, often told Renshaw they returned home to the "call of the mountains." He spoke to researchers in Colorado who reported the same trend: People born and raised in the mountains moved to lower land and found themselves longing for their home state.
As anyone who saw Gravity knows, oxygen density decreases as altitude rises. Oxygen deprivation from high altitude induces a condition called hypobaric hypoxia, which ranges in severity based on how little oxygen is available. Some hypoxic effects are well known — nausea and headaches from altitude sickness, nosebleeds and lower alcohol tolerance, for example. But while physical afflictions associated with hypoxia have gained academic and mainstream attention, scientists have largely ignored its potential impact on mental health.
Renshaw believes that oxygen-poor air tampers with brain chemistry, leading to a drop in serotonin and an uptick in dopamine. Serotonin and dopamine are neurotransmitters, brain chemicals that relay signals between neurons and other cells.
Serotonin, an inhibitory neurotransmitter, helps stabilize emotions. Antidepressants — SSRIs, (selective serotonin reuptake inhibitor), which include Prozac and Lexapro — work by blocking the transport of serotonin back to the neurons, thereby increasing its supply in the brain.
Dopamine, an excitatory neurotransmitter, plays a vital role in our ability to focus. Too little dopamine can make us scatterbrained, whereas a dopamine increase causes hyper-concentration and feelings of euphoria. Caffeine, prescription drugs, including some ADD/ADHD medications, and illegal stimulants like cocaine and methamphetamine, work by increasing the availability of dopamine in our brains.
So why do some people enjoy the benefits of the Utah air's impact on increased dopamine levels, which should make us happier, and some fall victim to the impact on decreased levels of serotonin, which would make us more depressed?
The answer lies in how changes in neurotransmitter levels affect our individual brain chemistry.
As Renshaw's theory goes, serotonin deficiency exacerbates symptoms of pre-existing anxiety and depression, increasing the likelihood of becoming suicidal (mental illness is a factor in about 90% of suicides). People with an existing mood disorder, or a predisposition to mental illness, would be more sensitive to the effects of waning serotonin levels.
But those without a predisposition to mental illness will, on the flip side, feel happier. By Renshaw's estimates, the brain makes about 20% more dopamine in the mountains.
Others didn't see it like he did. When Renshaw peddled his altitude-suicide theory around the mountain states in 2008, he faced prickly reception. Renshaw heard that Utah's governor at the time, Jon Huntsman, was disgusted that the state would fund the anti-Utah research. Huntsman's staff did not respond to a request for comment.
Doug Gray, a suicidologist at the University of Utah, has been studying suicide in the western mountain states for over 20 years. Whenever he makes a presentation, Gray said, he asks audience members why they think the region has such high suicide rates. People generally offer a cultural explanation, but Gray's never been persuaded.
"Nevada and Colorado also have high suicide rates," Gray said, reflecting on theories ventured over the years. "You tell me how Salt Lake City and Las Vegas have the same culture."
About six years ago, Renshaw caught Gray's presentation at a conference where Renshaw was also scheduled to speak. Gray posed his usual question to the audience and, per Gray's recollection, Renshaw raised his hand and said, "Did you know that at high altitude, the brain goes through metabolic changes, and some people can adapt while others can't, based on their DNA?"
Gray's jaw dropped.
"Well," Gray recalls saying, "that would explain it."
Renshaw's work, in Gray's opinion, won't gain mainstream acceptance for a while. But, he believes the theory is only getting stronger, as Renshaw corroborates the mental illness-altitude connection through animal studies and clinical trials for natural substances to help treat some hypoxia-induced mood disorders.
