Tracy’s answer to “Is this a suitable 'teen read', or is it aimed at an adult audience? Thanks” > Likes and Comments

True--the suicide do-over could be triggering, especially if you're old enough--or unlucky enough to know a lot of dead people. Friends, family, people you love who died too early, both of natural causes, drugs, illness, and yes, suicide (you always wonder about all the drug OD deaths--are they suicide? You never really know.)
Other than that, though--I thought it was a pretty light-hearted theme about Physics and parallel universes. Not cool about the suicide though; you are right. We always say:
Permanent solution to a temporary problem. Problems are always temporary--no matter if you are doing GREAT today, or feel like shit--that is going to change. Nothing constant but change.

It is pretty clear what this book is about and the subject matter needs to be addressed because it is something real that is being explained through a fantasy concept. Take away the stigmas and people need to be open to the real world of mental health. It absolutely talks about the finality of death because that's what it is -- a final end. It is a statement that we are more than our regrets and that we can rise above them and take a second chance.