3.5 stars. 
 There are positives and negatives to this book, though ultimately I found the good outweighed the bad. So, 3.5 stars. 
 Firstly, I found the portrayal of Audrey's anxiety disorder refreshing, in a way. I have read, seen and heard so many stories (both fictional and not) in which people, teens in particular, claim to have social anxiety issues because, OMG, they get like so awkward around cute boys and hate speaking in crowds. This take was much more realistic. I also liked the portrayal of her family, and those around her, and how they were coping. 
 I enjoyed the therapy session scenes with Dr Sarah as well - being a YA book means a large part of its audience is at that young, vulnerable age and I think there are really good messages and pieces of advice and wisdom in here that would be great for them to read. 
 Also, I just plain old enjoyed reading it. It was humorous, if not laugh-out-loud funny, I liked the characters, I liked the story and I liked reading it. 
 I've seen a couple of reviews saying they thought the secondary story line - Audrey's mothers fears about her son Frank being addicted to video games and computers - over the top or unnecessary but I disagree. I thought this made the story more realistic and 3 dimensional. Yes, Audrey has issues and yes, her family's very concerned and supportive of her but that's not the only thing going on in their lives. As for the over the top part, well, maybe these reviewers don't have computer addicted siblings... I do (my bro) and this actually brought back so many memories of our teen years. He's a software developer now so it all worked out ok. 
 The negatives... firstly, I understand Audrey is 14 and this is a YA novel but I did find her language, like, a bit tedious. Or whatever. 
 Secondly, although I initially liked the realism of her symptoms, I did find her 'recovery' a little suspiciously speedy. There is a scene (near the beginning) where Linus writes her a note. She immediately writes a message back to him and makes an effort to make her little brother Felix go give it to him. I'm sorry but if her disorder is as serious as it's supposed to be, would she not spend ages agonizing over whether to reply and whether she can, then exactly what to say, how her handwriting looks, whether it's too late to reply now she taken this long agonizing? Then feel relieved when Felix doesn't go at first, then freak out again, then convince herself to make him go? I mean, I'm not saying I have any social anxiety issues, but if I did, that's what I'd do... 
 And lastly, like others have said, there is a *lot* of hinting throughout this book to some big incident that happened that basically triggered her entire anxiety and depression onset (AS WELL as someone else's, we discover!) and WE NEVER FIND OUT WHAT IT WAS. Seriously. And that's not a spoiler, just a warning - I'd have to know what happened to spoil it....