Session 9 (2001)

Continuity mistake: Gordon mentions that his wife accidentally spilled hot water on his leg and burnt it, but the actor only occasionally limps on it, although we are shown that he has an injured leg. This is mentioned on the commentary.

Factual error: When Mike first starts listening to the session tapes, the camera does a slow pan down the label on the box. Quite clearly, we can see that the patient's diagnosis is listed as "D.I.D.", along with a few names. Since the hospital closed in the mid 80's, it is not possible for her to have that diagnosis. Before the early 1990's, D.I.D. (Dissociative Identity Disorder) was known as M.P.D. (Multiple Personality Disorder). In later scenes it is correctly listed in the woman's files as Multiple Personality.

Continuity mistake: When Gordon is remembering the day he went home and his wife spilled the hot water on him, it shows Gordon in the van watching his wife and daughter walk into the house. They disappear around the corner, but in the next shot of the house his wife and daughter are walking into the house again.

Trivia: The film was shot primarily at the Danvers State Asylum, an abandoned hospital. The script was written around the shooting location based on what rooms and corridors were safe to shoot in. Little to no set-dressing had to be done for the film, as it was suitably dilapidated and filled with abandoned medical equipment, which helped add to the film's atmosphere.

TedStixon

Trivia: The movie was filmed on Sony High Definition camcorders as opposed to traditional 16 or 35mm film. The camcorders used were among the first to offer the cinema standard 24 frames-per-second as an option (as compared to the home-video standard of 30fps) which helped make the image look closer to cinema-quality. The movie was one of the first mainstream films shot primarily on digital video.

TedStixon

Trivia: A massive subplot was removed from the film. It was going to be shown throughout the film that a crazy homeless woman was secretly living in the hospital. She'd eerily observe the workers and be a red herring to throw off the audience. SPOILERS. Finally, after she witnesses Gordon kill everyone, she would sneak up and kill him as "revenge." However, her subplot was removed as audiences were confused (thinking she was Mary from the audio tapes) and the director wanted to streamline the plot.

TedStixon

Mike: Satanic Ritual Abuse Syndrome. It was big in the '80s.

Henry: What are you... doing... here?

Henry: So, the loonies are out in the real world, and here we are with the keys to the loony bin, boys.