It is based on a true story. But the story actually happened in Bavaria, and the girl's name was Anneliese Michel. She was in her early 20's. And she did die as she was exorcised. The priests that performed the exorcism were put on trial for negligence. The priests argued that the possession was real.
There are some differing views:
The ultimate escalation of mythomania is not only telling stories and believing them, but acting them out. There are innumerable historical episodes exemplifying this type of mythomaniacal enactment, with the classic case being "possession." The state of being "possessed" signifies the escalation from being a mythomane to being a "demonopath," a person claiming to be suffering from demonic torments. The demonopath is far from being a passive victim of his or her affliction and was often the active initiator of witch panics, playing an aggressive role in the prosecution of witches.
Also, the demonopath is far from being a historical relic. The case of Anneliese Michel deserves mention, if for no other reason than to demonstrate historical continuity of religio-cultural images.
That was the Freuds and their take on the case. I believe demonic possession's can and do happen - despite what the freuds say. The only question I have is whether or not this girl was truly possessed.
This is just freaky:
Pastor Alt and Father Renz try to save Anneliese from, in the meantime over 6 individuals (Lucifer, Judas Iscariot, Nero, Cain, Hitler and Fleischmann, a disgraced Frankish Priest from the 16th century, and some other "Damned"), which manifested thru her.
I'm guessing that's the same Hitler we all know. I wonder whether he'll appear in the film or not. The interesting thing about all of this is that a full fledged Christian writer is behind the movie. Which probably explains why it hasn't been destroyed in Hollywood anti-religious fanaticalism.
The exciting thing about this movie is it asks the question: are demonic possessions for real? I believe they are. Most people brush it off, saying these people are mentally ill, or have some other explanable decease. But the Church isn't so stupid. In this case, they initially refused to perform the exorcism in favour of conventional treatment first. When that didn't seem to be working, and the required evidence was there, they did what needed to be done.
It puts the question on the table. And that's the important thing. If they really wanted to make money with this thing they would consider marketing it the same way the Passion was marketed. But so far, it's getting little attention.