I'm not sure, but it is an idea that has crossed my mind. About 9 years ago I had a very VERY powerful experience on drugs. I tried many different drugs in the past (now no, not for years)however this one time stands out by a LONG way. One thing I remember about this experience is that I remember the feeling of a deamon or evil spirit entering my body. Interestingly, when I think about it, it was around exactly this time that my eating disorder started. This is the number one thing that has changed and ruined my life, not only is technically slowly killing me in itself but also drives me to crave suicide.
Of course, this experience is a long time in the past now, so I put it behind me and don't really think about it or take it too seriously. But, going by your theory...it could be true