(This review contains spoilers.)

“I can’t remember when this journey began,” Caden Bosch tells us, near the start of Neal Shusterman’s “Challenger Deep.” “It’s like I’ve always been here, except that I couldn’t have been, because there was a before, just last week or last month or last year. I’m pretty certain that I’m still fifteen, though. Even if I’ve been on board this wooden relic of a ship for years, I’m still fifteen. Time is different here. It doesn’t move forward; it sort of moves sideways, like a crab.”

The journey that Caden is describing isn’t exactly what it seems. Though he describes the ship in vivid detail, along with the captain, the crew, and even the captain’s parrot, the truth is that none of it is real. Caden Bosch is in fact an ordinary American 15-year-old boy in an ordinary family, going to an ordinary school. But what’s happening in his mind is anything but ordinary. Caden is suffering from severe mental illness, and his imaginary life on the ship is his mind’s way of interpreting what’s happening to him.

Bestselling novelist Neal Shusterman based “Challenger Deep” on his son Brendan’s struggle with mental illness, and the book includes several of Brendan’s drawings. The book has earned considerable critical acclaim, and won the 2015 National Book Award for Young People’s Literature.

Though it’s hard to really get to know Caden as he slowly loses touch with reality, to the point where he finally has to be hospitalized, he still manages to win our sympathy and support. Shusterman is an excellent writer, who deals with this tough topic with both frankness and sensitivity. And the book is full of beautifully written passages that make both Caden’s real life and his imagined one come alive.

Nonetheless, I sometimes wondered if “Challenger Deep” might be one of those books that wins praise and awards more because adults like it than because teenagers will. As Caden’s narrative shifts back and forth between the real world and the world of the ship, without transitions or explanations, the reader shares his sense of disorientation. In one way, this works well, as it helps us to identify a little more easily with our troubled protagonist. In another way, it doesn’t work quite so well, as it makes the book so confusing and hard to follow at times. Also, I believe — though I’m not quite certain — that there are some jumps backward and forward in time, which make things even more complicated.

As much as I admired and appreciated Shusterman’s effort, there were times when I got a bit lost and found my mind wandering, which makes me wonder what the teen reading experience would be like. While some teenagers probably do just fine with the book, others may struggle.

As for the subject matter, there’s occasional violence on Caden’s “ship,” and occasional profanity, but very little sexual content (it’s limited to Caden telling us that his medications have lowered his sex drive). There are a few religious references — sometimes neutral, sometimes positive, occasionally sarcastic — and some drinking. But of course the main topic is a tough one for readers of any age to deal with.

Caden’s illness, and that of the other kids in the hospital, is handled with both realism and hope. Caden hates the hospital and hates the drugs, even while at some level he recognizes the need for them, and he knows that the treatment is far from perfect. But it brings him to the point where he’s able to function again, and is able to take life a day at a time, without the devouring anxieties and hallucinations that once plagued him.

One friend of Caden’s in the hospital, Hal, doesn’t do so well. He goes off his medication, as does Caden at one point — but unlike Caden, Hal commits suicide. (Caden never finds out for sure whether Hal’s attempt was successful, but he suspects that it was.) Caden himself doesn’t want to commit suicide — if nothing else, he believes his love for his little sister will keep him from it — but he can imagine all too easily what led to it:

I still can’t figure out if it’s bravery or cowardice to take your own life. I can’t figure out whether it’s being selfish, or selfless. Is it the ultimate act of letting go of oneself, or a cheap act of self-possession? People say a failed attempt is a cry for help. . . . It’s more a cry to be taken seriously. A cry that says “I’m hurting so badly, the world must, for once, come to a grinding halt for me.”

The question is, what do you do next? The world stops, and looks at you lying there with your wounds bandaged, or your stomach pumped, and says, “Okay, you have my attention.” Most people don’t know what to do with that moment if they get it. Which makes it definitely not worth the cost of getting there. Especially if that failed attempt accidentally succeeds.

Clearly this is not a book for every teen. But with parental guidance and discussion, it might be a good book for some. Despite the difficulties, it does a good job of dealing with a problem many teens have to face in themselves or in their families or friends, without either glorifying it or wallowing in it.

Image copyright HarperTeen.

Gina Dalfonzo is editor of BreakPoint.org and Dickensblog.