A Head Full of Ghosts, a novel by Paul Tremblay, explores the intense psychological and supernatural ramifications of a family's struggle with mental illness and the possibility of demonic possession. The story centers on the Barrett family, particularly the teenage daughter, Marjorie, who exhibits increasingly erratic behavior. As her condition deteriorates, the family becomes engulfed in turmoil, leading them to seek outside help, including the influence of reality television to document their experiences.
The narrative is presented through the eyes of Merry, Marjorie's younger sister, who reflects on the traumatic events from her past. The tension escalates as the line between reality and the supernatural blurs, making readers question whether Marjorie's issues are rooted in mental illness or if something more sinister is at play. The family's desperation and the media's exploitation of their situation highlight themes of fear, judgment, and the impact of mental health stigma.