Honestly, I believe that this whole sphere is ripe with, and a perfect place for, charlatans and confidence men. That said, a friend got me into a pretty deep study about this a few months ago, and, I do believe that American's de-emphasize this aspect of spirituality based on what I have read and personally experienced.
If you want to get deep into this topic, I would suggest some stuff from Michael Heiser, who goes pretty deep into the biblical basis of demonic influences, and the differences in what we read in the OT vs NT about spiritual warfare. It was really enlightening, but it opens up a whole new can of worms.
You get into this very far, and you are going to run into people that see demon possession EVERYWHERE. I'm not sure I agree with all that, but I do thing that Enlightenment / Western society has de-emphasized it.