There are some stories that simply need to be written. Stories like Eleanor & Park, Skin and Bones, and Rebels by Accident that tell tales of people who aren't often addressed and carry important messages. Sometimes, it's on a small scale, sometimes it's grand, but nonetheless these stories are important and are needed to be said. To me, Challenger Deep is one of these stories. It takes a different approach on mental illness than I've seen before in novels. It's less sensationalism, and feels more honest, which makes sense given the experiences detailed in the book are inspired by events that Neal's own son has gone through. It broke the mold of novels about mental illness. 
 It doesn't start with Aden in the hospital, after the spiral, the mental break, the "catastrophic event." At least, not entirely. Instead Challenger Deep leads up to it, with interjections from Caden's ocean journey to provide the reader with insight into how his mental illness operates. We, the reader, get to see what Caden is as he is at the cusp of his mental illness, and how his conditions steadily worsens. 
 In addition, what's unique about this book is the way it addresses the underlying cause of mental illness. It's not seen as a side effect of some terrible trauma. Caden isn't abused, he hasn't been abandoned by his family or witnessed them die horrifically. His family is actually really nice, and they genuinely care about him, while still suffering the everyday faults families typically have. His mental break doesn't occur because of something done to him, it's simply something that happens to him. They're no dramatic reveal at the end of the book, where the author pulls away the curtain and suddenly the characters and the reader both realize just why the mentally ill character behaves this way, and with the past trauma revealed they are able to pin blame on something and are healed. And I'm not saying those stories aren't important. It's just that those are the only stories being told. Over and over again. And that's not what mental illness is like. It just... Happens. I've seen different percentages, like that one in five people are afflicted with some form of mental illness, and Shusterman cites that one in three families are affected by it. And (though I don't know exact statistics) not all of these are because of some past trauma. Mental illness is something that simply happens, without reason other than brain chemistry. And that's fine. That's actually kind of normal. And this book addresses it. 
 Finally, this book is so important because of how Caden's family reacts to his mental illness. They're scared, yes. But not of him. The parent's don't know what is happening to their son, they don't know what's wrong, although they know something is different. And they try to help him. They never abandon him. They show that they're not disgusted by him, that being mentally ill and having a loving and supporting family aren't mutually exclusive. And this is so important because it's not something I've really seen in books about mental illness either. His family was such a huge presence and it felt so real and authentic, but also reassuring. 
 Finally, the ending. (view spoiler)[I wasn't sure how I wanted it to end. I know I'm horrible, but originally I wanted it to end badly. Because I was worried what would happen if it didn't. I didn't want Shusterman to simply brush over the impact of mental illness. It may be something normal, but it isn't something to dismiss with a neat "they lived happily ever after" and a bow tied on top. But as I grew to like Caden and his family, I wanted it to end well for him. Despite my doubts and misgivings. And I can say that it ended as well as it could have. Caden and his family on the boardwalk, with the Captain approaching him again with the lure of another adventure. And Caden refuses, while also acknowledging that one day, sometime he will eventually say yes. He will go with the Captain, he will again have to go back to a facility. But not today. Today he is fine, and he will continue fighting for as long as possible. And that felt like the perfect ending. It was hopeful with a dose of realism, and made me feel utterly satisfied. (hide spoiler)] 
 In short, while I didn't give this book five stars, I loved it and believe it is an incredibly important novel to have been written. Even if it's not something you would normally read, I recommend it just for the insight it gives into mental illnesses, and for the knowledge that this is not someone writing for the sense of sensationalism. This is someone writing from experience, from something that has touched his own family, and I believe Shusterman has done a remarkably good job of it.