Crazy, by Han Nolan, is intense and sad and funny and beautiful. 15yo Jason is trying to live a normal life with his schizophrenic dad who is obsessed with Greek mythology. He doesn't want anyone to know what's happening at home, but he also can't cope much longer. I have a couple of loved ones with brain disorders, and how they would cope with being a parent is always a big question. A stolen violin, a school counseling group, and an anonymous advice column are just a few of the elements expertly woven throughout this novel. One of the best I've read this year.
I also really liked Small as an Elephant, by Jennifer Richard Jacobson. (Small-scale spoiler alert) This mg novel features an 11yo main character whose mom disappears on a camping trip. He, too, is trying to keep his parent's illness (in this case, bipolar) a secret, because he doesn't want to be separated from his mom. So he's trying to find his way home without bringing attention to the fact that his mom has abandoned him.
Both of these novels acknowledge that one of the hardest truths about mental illness is that there's no easy cure. And a child trying to keep a household together and take care of a mentally ill parent is in way over his head. But taking a kid away from a mentally ill parent is traumatic, too. No easy answers, but both of these books are tribute to the power of friendship and of caring adults to help find the best situation possible.
Even though I especially enjoyed these books because of their topic, they are not "problem novels" to be given to kids in similar situations. They're just really good books!