[tallanvor]

Your assumption is that these factors could not be intertwined.

I would submit the following hypothesis:

As the nation moves in a direction where religion plays a smaller and smaller role culturally and legally, many follows of religion double down and attempt to prevent their children from moving in that direction. In places with a lower percentages of people who consider themselves religious - or at least very religious, this crackdown happens less, but when it does adolescents have other friends or family they can turn to for support. More insular communities - such as Mormons - do not offer the external support structure to young people, leaving them fewer options they see as viable.

So while this is not necessarily a problem only in the Mormon community, it certainly is exacerbating the problem.