It's so sad to realise that Ned Vizzini killed himself in 2013, 8 years after writing this book. I have suffered from depression for many years now, and this book represents some recognisable aspects of depression. 
However, the main character and Ned Vizzini himself only stayed 5 days in a psych hospital. I really don't think that 5 days is enough to treat severe depression like the ones Craig and Ned Vizzini had.
And I thought the book had more emotion, but honestly, the whole story felt kind of flat for me.