Impulse discussion

Can someone give me a summary of this book, because I think I've read it before, but I don't know for sure...

Tony, Vannessa and Connor are all admitted into a psychiatric ward after attempting to commit suicide. Tony has a drug problem, Connor tried to shoot himself and Vanessa cuts herself. They all meet at the ward, and become really good friends. Thats basically it, except for a huge twist at the end.

Ok. Thank you :)