MitchPeeThis is an interesting theory. However, it doesn't really hold any credence in relevance. By his theory, Colorado should be the epidemic, not Utah. Colorado's average elevation and standard deviation of elevation in comparison to the rest of the country far exceeds that in relation to Utah.
My opinion is that it is the social structure in Utah that sets it up for suicidal disaster. Having lived here for quite a while and also living in Japan for years, I see a correlation between the two. They are both extremely conformitive societies. In Japan, there is no such thing as an individual. You are Japanese and you must obey and adhere to that which makes you a part of the Japanese community. This works to keep a society in order, but the backlash is that some people are withheld from gaining any sort of physiological fulfillment. Creativity is squashed within this social structure. Thus, those who are naturally ambitious, curious, or just don't conceptualize the same values that the majority do are found conforming to the general norm by massive amounts of social pressure. Mormonism is very much the same. So many people are forced to conform to a decree held in their family under the guidance of the LDS church. They marry young, their important decisions, and their entire lives are completely revolved around conforming to a mold that they must fit into as designated by the LDS church. Questioning or exploring other options in life will get you excommunicated from your family in a lot of instances.
It's this social pressure that creates a strong counter-culture in Utah. It's obvious when you live here that there's a sect in the population that was raised here (especially during the 70's, 80's and early 90's when Salt Lake was very much Mormon) and is just not normalized in a way the rest of the country is. Their mannerisms and perspective of life is much different than counter culture in other regions of the country. Take a look at SLC Punk, the abundantly young rave scene, etc. It's a big fuck you to the tight control the LDS church used to have over the large portion of society and is a direct result of too much pressure creating backlashes in radical positions.
Given the fact that the Utah "culture" is becoming more assimilated as people from throughout the country move in, I would bet that the suicide rate would decline due to the easing of social pressures from the LDS lifestyle and an all-around mixing of social ideology.
spliff.Life^that makes more sense.
I think cultural explanations are worth consideration and the comparison to Japan was on point however the suicide belt includes all the rocky mountain states, not just Utah. While cultural factors could contribute to Utah being a hot spot for this issue, depression and suicide rates are disproportionately high in all rocky mountain states; most of which have very different cultural conditions from Mormon Utah.
Also there is empirical evidence that altitude has effects upon dopamine and serotonin levels, as rats who were exposed to simulated high altitude conditions had much lower serotonin levels but much higher dopamine levels.
However, this is still just a theory at this point and doesn't have enough backing to make it fully legitimate.