Just to be clear, it's not a bad movie. The idea, the plot and the acting are good. It's just that they didn't present the plot in a good architecture.
It starts fine, Jane, the psychiatrist is surprised during the night at her work place by a teenager patient of hers. The girl had self-inflicted cuts all over, and then brutally attacks Jane who kicks her away. Then, the girl slits her own throat.
Some time latter, we learn that Jane is now in therapy with a psychiatrist, while having her own patients at home. She's got a boyfriend, who is a cop, and the girl was committed to psych ward. Jane is still haunted by her memories and nasty nightmares. Who could blame her?
So, she decided to take on a difficult patient, a man whose face had been disfigured. Her own therapist is against it, since she is not ready to go back to hardcore cases. But she does it anyways. The patient starts to behave like a nut job. So she dumps him. For a while. Once again, who could blame her? She's got an human heart.
She starts having vision about the girl in her home, and learns she had left he psych ward, due to lack of paying the bills. Stuff happens, she almost looses her mind, suffers other attacks...stuff you'd expect in this kind of movie. Then she steals some of her doctor's prescription papers so she could buy heavy meds. It all turns sour and she goes nuts, and ends up killing the boyfriend.
She wakes up at the same psych ward her former patient was committed to. (You gotta appreciate the irony here.) Then, when she was about to loose the rest of her sanity, she puts all the pieces together (dunno how) and finds out that her disfigured patient is actually the girl's abusive father. It was the girls who had slashed his face off (he had claimed to have suffered a car crash). Also, she is told that the girl hung herself and was found three days afters; when someone close by noticed the smell.
So, Jane runs away from the psych ward, and is captured by disfigured-dad. He takes her to her home, and she sees the dude had killed her best friend and her doctor. Of course there's that cliché moment, when the bad guy believes he's gonna win (don't they ever learn?) and tells Jane the entire story. They fight, but not very well (if you're used to watch U.F.C., you won't like this fight very much); he gets beat up, she gets beat up. Then, at the end, she rips what was left of his face (she grabbed his face as she was falling from the second floor window). She enters the house again and finds faceless-dad sitting on the couch, dead.
Then the movie ends. And so does this review (I mean, what can I do? There's nothing more to say.).