I haven't seen the movie of this (despite being told to by countless different people) so I, A) can't compare and, B) went into this knowing actually very little about it. 
 It was a good book and I enjoyed reading it. It was a little slow but it's the sort of book that needs to be, I think. It was well written and - from what I've heard and as far as I can tell with my very limited experience - an accurate look at mental health, both the sufferers and their loved ones learning how to deal. 
 The characters felt very real. I especially felt for Tiffany - I couldn't help imagining myself in her position and I think that if my partner, whom I love with all my heart, died that I would go a little 'crazy' too. 
 It wasn't a 5 star read for me as it was *slightly* slow and I just didn't love it like I do my 5 star reads - such as Forgive Me Leonard Peacock by the same author - but I did really like it. Also there was a lot of talk about American Football which, as an Australian, I am not particularly interested in (I do like that he supported The Eagles though since my Australian rules football team is also called The Eagles. But I digress). 
 Also, 'Crabby Snacks' sound really, really good and I'm going to try making them asap.