Here's a bit about A World Without You from Goodreads:
Seventeen-year-old Bo has always had delusions that he can travel through time. When he was ten, Bo claimed to have witnessed the Titanic hit an iceberg, and at fifteen, he found himself on a Civil War battlefield, horrified by the bodies surrounding him. So when his concerned parents send him to a school for troubled youth, Bo assumes he knows the truth: that he’s actually attending Berkshire Academy, a school for kids who, like Bo, have "superpowers."
At Berkshire, Bo falls in love with Sofia, a quiet girl with a tragic past and the superpower of invisibility. Sofia helps Bo open up in a way he never has before. In turn, Bo provides comfort to Sofia, who lost her mother and two sisters at a very young age.
But even the strength of their love isn’t enough to help Sofia escape her deep depression. After she commits suicide, Bo is convinced that she's not actually dead. He believes that she's stuck somewhere in time — that he somehow left her in the past, and now it's his job to save her.
Doesn't it sound awesome!?
A World Without You is due out next month from Razorbill.