1.5 stars . . . for the cover. 
 I was really prepped to like this one, because while I absolutely cannot watch scary movies, I can easily dive into a scary book. A good horror genre novel will make you stop reading, it's so scary. It will constantly creep into your brain, even during the safe daylight hours, and haunt you at nighttime, where every little noise could be the creature or phenomenon or what-have-you. 
 Asylums are freaking scary, just off the top. We all know about EST and lobotomies and creepy stuff like that, so I was fully expecting a haunted, murderous asylum a la Stephen King... but toned down a little for the YA crowd. 
 This I did not find. 
 The plot was . . . weird. The supernatural elements were not sufficiently explained, there was a lack of spine-tingling suspense, the writing was simplistic and not captivating. The ending was unsatisfactory. You could also see the bad guy coming a mile away. 
 I could deal with this, but . . . it wasn't scary. The scariest thing that happens is Dan finds a body. It doesn't jump out at him, he doesn't touch it thinking it's something else, no, he just looks and sees it. Even when he's creeping around in the basement of the old wing, the most I feel is a slight sense of trepidation - is something going to happen? - followed by general annoyance when, no, nothing happens. 
 The characters were meh. Jordan, I found particularly annoying. Because of the obvious tension within the "threesome" I found their friendship unbelievable. And, like others have cited, I would have understood Dan and Abby's relationship if it, 1) led to some revelation or 2) resulted in character development. But neither happens. Instead, they go on an awkward date, in which Dan is jealous. Then they run off to poor baby Jordan, who has to be coddled by Abby, and whom Dan does not even really like (for good reason, because he is a jerk). 
 If you want good YA horror, try Rick Yancey's Monstrumologist series. Gore, well-rounded characters, and spine-tingling scariness (and monsters!) abound.