“Horror movie The Exorcist remains one of cinema’s darkest and most frightening classics. So great was its power that rumours circulated about viewers running in fear, feinting, or even going mad after seeing the film. In fact, it caused such concern that it was discussed in the medical literature for its possible role in triggering mental illness.

In 1975 psychiatrist James Bozzuto wrote an article for the Journal of Nervous and Mental Disease entitled ‘Cinematic Neurosis Following The Exorcist‘ that reported four cases of previously untroubled people who seemed to develop psychiatric difficulties after watching the film…” (Mind Hacks)