A Head Full of Ghosts by Paul Tremblay

The lives of the Barretts, a normal suburban New England family, are torn apart when fourteen-year-old Marjorie begins to display signs of acute schizophrenia.

To her parents’ despair, the doctors are unable to stop Marjorie’s descent into madness. As their stable home devolves into a house of horrors, they reluctantly turn to a local Catholic priest for help. Father Wanderly suggests an exorcism; he believes the vulnerable teenager is the victim of demonic possession. He also contacts a production company that is eager to document the Barretts’ plight. With John, Marjorie’s father, out of work for more than a year and the medical bills looming… Read more.