The answer is all of the above. This story is important for teenagers because it gives several good lessons. First of all, it tells you that you never know that what can really happen with you. Secondly, it tells us that life can sometimes be totally different from what it looks like from the outside. Thirdly, it tells us that there are different ways of handling different problems, and everyone uses his/her own way.
This is what Impulse revolves around, which a 2007 American novel is written by Ellen Hopkins. This novel talks about the difficulties that three troubled teenagers go through, in a hospital while they try to work their way out.