'The Things A Brother Knows' by Dana Reinhardt

Levi and his family wait for three years for his brother Boaz to return from serving in the war in the Middle East. When he comes home though, he is different.  Bo never leaves his room, will not talk to his family, and refuses to ride in a car.  Weeks after returning, Bo announces that he will be leaving for the summer to walk the Appalachian train.  However, Levi starts snooping around on Bo's computer and finds out that he has much different plans.  Levi decides to walk with him in an attempt to understand his brother and what happened to him when he was overseas.

Dana Reinhardt does an excellent job of showing the psychological effects war can have, not only on soldiers, but their families as well.