The "devil" as many believe it/him to be, doesn't exist. Demons, assuming the non-christian ones which are also not real, no. I'm strong minded.
One such disease linked to "possessions" is alien hand syndrome. This is where your hand seems to have a mind of its own. People with this syndrome usually can not control their hand. Pseudobulbar palsy is where you are unable to control your facial expressions. This can affect how one eats or talks. Capgras delusion is where a person thinks there are identical twins of a close family member. They can also misidentify a person as well. There's many more that debunks possessions.
Demons nor the devil exists. Scientists, and even I, can explain several things that happen during a demonic possession that are not supernatural but real life. Although there have been some weird and odd demon possession stories that are claimed to be true, I guarantee that they have been debunked already. Nobody has ever been possessed before, it's all in our heads. Also, I don't think you can be possessed by the devil himself, only demons, as far as I know.
Heheh. who knows?
wow, this is a serious topic ^^ i'd say if i'd been posessed by a demon, it would definately been for a heck of a reason. but then again, it's hard to say that when it's happening, huh??
Not that I know of...
Demons don't exist, and I'd say the same for the devil, but I've got about three different friends who claim to be him/her/it so apparently I'm not allowed too.....
But in short, no. Unless yes and I just don't know, althoguh that's be illogical seeing as they don't exist.
No, not yet at least.