There are. I'm a recovering alcoholic and have spent a lot of time talking/listening to recovering addicts of much harder drugs. Many of them have described chillingly similar visions of hell and demonic beings. Certainly it's easy to write these off as hallucinogenic byproducts of their addictions, but the similarities between their accounts coupled with the sincerity and fear in their eyes when relating their accounts suggest to me that it's something more.
If that is their experience it should be enough to scare the hell outta them and set them on a new path.