I felt that Deborah's sickness was both original and convincing and I liked that she didn't have some kind of huge, dramatic memory that influenced her sickness; that it was almost totally out of her control. I mean yeah, bad stuff had happened to her like with the surgery and the summer camp, but everyone has bad memories and traumatic experiences.
I liked the other characters as well, especially because they were all so incurably disturbed and had their own behaviors and symptoms.
My only qualm was the ending. It felt a bit rushed to me, like it didn't tie up as many loose ends as I would have hoped, for instance, Deborah's family. In the last chapter or so it felt as if they kind of disappeared.
Either way! Loved the book, definitely recommend it.