Having been raised Mormon and participating in the church and culture until my mid-20's, there are sooo many aspects of the religion that affect life across so many dimensions. I'm sure abstinence from drugs is benificial, but probably only account for a fraction of the effect.

Other things I'd consider:

* Longevity is associated with community, something the church is very good at

* Even elderly individuals are required to perform "a calling", giving them meaning and purpose later in life

* Mormons have a lot of children, and so when you're older you usually have a very strong social safety net

* Mormons have lower divorce rates, and divorce is correlated with greater mortality

As an agnostic and raising kids, I spend a lot of time now pondering how – if at all – to pass on as many of these benefits of Mormonism to my kids without mandating the magical beliefs, and I have to say it's difficult. But I think you do have to have some healthy middle-ground mix of conservatism and collectivisms just to strike a healthy balance with modern individualism and liberalism.