Trivia: Altered States
- Creator Backlash: Paddy Chayefsky, author of the original novel, disowned this film. Allegedly he took his name off the film because of creative differences between himself and the second hired director, Ken Russell (see Christianity Is Catholic).
- Dawson Casting: Then 33-ish year old Blair Brown plays a 24-year old Emily at the start of the film and presumably by the end of the film is playing closer to her real age. She's also meant to be somewhat younger than Eddie but in real life Blair Brown is actually 4 years older than William Hurt.
- Troubled Production: Arthur Penn, the original director, quit early on after a dispute with Paddy Chayefsky, who was upset with some of the changes he'd wanted to make. John Dykstra quit as well, and Bran Ferren had to do the special effects on a lower budget. Once Ken Russell was hired to actually finish the film, he was in a situation where, if he changed so much as one word of the script, he'd have been sued, so he resolved it by having the actors deliver some of the more pretentious dialogue very rapid fire. Chayefsky didn't sue, but was still pissed enough to petition the Writers' Guild to use his given name, Sidney Aaron, in the credits as his pseudonym for the screenplay. Maintaining that the film still followed the script to the letter, Russell later criticized Chayefsky as "impossible to please" and at one point actually had him thrown off the set for interfering with his direction of the actors when Chayefsky objected to their delivery of his dialogue. The experience of shooting some of the scenes was very trying physically for the actors. Columbia, who had started the film, washed their hands of it and Warner Brothers picked it up. The producer was nonetheless upset that they decided to shove it into the Christmas season rush rather than wait until the spring when he there would be less competition for that kind of film.