Even though I think the wave of writing about mental illness is ebbing, this is still a fantastic book that portrays what it's like from the person suffering the illness, and from the perspective of a loved one.
High-school Vivi moves to a small beach town over the summer and falls in love with Jonah, who has just lost his father suddenly due to a heart attack. The two collide, and it is good. Vivi is vivacious, full of fun, interesting, and goes about 90 miles an hour. Jonah is a typical hottie who doesn't know he's a hottie, but also more about taking care of the "littles" (his 3 younger siblings), working his father's restaurant to make sure it doesn't go under, and worrying about his depressed mother who hasn't left her bedroom in 6 months except to go to church. So the two get together, Vivi falls in love not only with Jonah but his family, too. But then things start getting a little too intense, and that's where it also starts to fall apart.
If you enjoyed All the Bright Places by Jennifer Niven, you'll enjoy this book. It's not as devastating as ATBP, but good just the same. And a very quick read!