A head full of ghosts

the long version

"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 bizarre outbursts and subsequent descent into madness. As their 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 for a reality television show."--Book jacket.