My guess would be that the difference in rates might have something to do with West being a society of Individualism and East being of Collectivism. I venture loneliness is liable to be more profound in the West as a result. For example, we have big families living together. 3 generations all living under the same roof. doesn't matter how rich or poor anyone is, the families stays together and sticks together. I've lived in Canada for 3 years during my post grad schooling, and i saw how different West is from East in this aspect. I blame loneliness as a root cause for majority of the vast MI everywhere in the world. It's the core root of depression, when it really comes down to it, which in-turn is the mother of a host of other mental disorders like anxiety, ocd, and whatnot.

Just my thoughts.