SALT LAKE CITY – America's Mountain States are known for sweeping landscapes that draw millions of tourists a year. The region is also known as America's "Suicide Belt," with rates twice or thrice as high as other parts of the country.
This problem baffled Perry Renshaw, a professor of psychiatry at the University of Utah. He never saw his fellow Utahns as more depressive than other Americans. So, he and a team of researchers devised a depression index, incorporating variables like the number of adults who had at least one major depression episode in the last year, and who had experienced serious psychological distress.
The swim test, developed 30 years ago by a French psychologist because rats don't show emotion, has a simple premise: Depressed rats immersed in water give up swimming after a few minutes, and are rescued by the researchers, while the happy rats keep treading water for at least five minutes. In this study, almost all the rats that spent extended time in higher altitudes gave up.
“The findings were almost too good to be true and that they look like they're drawn with crayons or something, because the effects are so very clear and strong,” Renshaw said. “The further you go up in altitude, starting about 2,000 feet, the more depression-like behavior you have.”
The results strongly suggested that the rats kept at high altitude had less serotonin to handle a situation of high stress. But when it comes to the flipside of the Utah Paradox – whether altitude can stimulate more enjoyment in a positive situation – there's another hormone involved: dopamine. And the researchers don't have a test for that yet.
Of course, Salt Lake City can't be razed to sea level. The Suicide Belt is stuck with its topography. But Renshaw hopes knowledge of the connection might be comforting to someone battling depression who lives in, or recently moved to, a high-altitude area. To overcome the condition, you don't have to move mountains; perhaps you just have to move you.
* Correction added Jan. 31: An earlier version of this article incorrectly listed a lower elevation for Sal Lake City.