The film in the English language has had a number of titles. These include: The Mind Snatchers, The Happiness Cage, Mindsnatcher, Brain Control, Mind Snatcher, The Demon Within, Mind Snatchers, and The Mind Snatcher.
Actor Ronny Cox in this film reprized his stage role of Sergeant Boford Miles from the 1970 New York theatre production.
''First major movie role'' of actor Christopher Walken according to a UK DVD release box cover.
This earlier movie featuring actor Christopher Walken shares some story elements with more well-known films starring the actor such as 'Brainstorm' (1983) and 'The Dead Zone' (1983).
One of at least two mind or body 70's ''Snatcher'' movies - the films are 'The Mind Snatchers' (1972) and 'Invasion of the Body Snatchers' (1978). The films starred actor Christopher Walken and actress Brooke Adams respectively. The pair later starred together in 'The Dead Zone' (1983) - David Cronenberg's film based on Stephen King's novel.