Never did. It would be impossible for me to deny such things happen. But then that's not what happened here.
Do people who take drugs to control their sanity or to gain mental clarity for example experience such incidents? Are users of Ritalin more susceptible to demonic influence?
Are you prepared to argue that negative? You want to tell Heather she needs to stop taking her meds?
The evidence, common sense testifies to the fact that what's happened isn't supernatural in origin with relation to bath salts: it's a chemical one influenced by the individual user, a choice.
If you or anyone else would argue otherwise, the burden is on you to make the case for this being an instance of demonic possession based on the facts.
Do you suppose Rudy Eugen had a history with the occult? Or maybe his drug crazed mind was influenced by the demon called ZAN?
(Zombie Apocalypse Now

)
God knows the truth of it whatever it is, but this side of Heaven the reasonable thing to assume based on what we can know is that he was just a self-made monster. A drug induced cannibal.
He's definitely not the first and he'll not be the last I'm sure.