I almost let my library loan run out before listening to this book, but I'm so glad I didnt. It's a really cool story that, while centering around a fictional diagnosis of "STWS", is actually reaching into some incredibly real problems many of us have. The book definitely follows an introspective journey for Amy, so besides her father, the rest of the characters don't have a lot of depth. But for this type of story I think it's best to be able to focus solely on the main character (and I do love the relationship with her father). It took me a few chapters to get really into the book, but by the end I felt really connected to it. 
As someone who could consider nostalgia a personality trait, and who sometimes considers whether it would be better for those around her if she disappeared, this book is not only relatable but deeply emotional. Would recommend <3