Barbara Hershey said, "I resent being put in the position of defending the film. We worked really hard not to make it exploitative. Rape is one of the ugliest, if not the ugliest thing, that can happen to someone. It's murder of a sort. I have no answer for those who are offended. They're right, but I don't think our intention was to exploit the subject, or the result. Truly, I don't. I think we did well with it." When Hershey was interviewed for the Scream Factory Blu-ray of The Entity in 2018, she had nothing but kind words to say about director Sidney J. Furie, even saying that going to work on it was fun and stress-free because he was at the helm, making her feel comfortable, safe, and protected at every turn. She also described it as one of the best creative experiences of her career.
The real-life Carla Moran's teenage son described a particularly vicious attack in which Carla was thrown by the malevolent force and hit her head. He tried to intervene, but he was also thrown, breaking his arm. In the filming of the movie, the actor playing the son broke his arm in that scene, and the curtains tore from top to bottom without explanation.
According to Barry Taff, the director Sidney J. Furie didn't believe the real-life story and just thought they were all a bunch of drugged-out wackos.
The method in which Carla is diagnosed by physicians, a method which relies heavily on her personal history, and in particular her relationship with her father and her sexual encounters with other men, reflects a largely Freudian psychodynamic method of diagnosis. This, combined with the fact that she is initially diagnosed by the team of doctors as having "hysteria," a disorder that has disappeared from mainstream American psychiatric diagnostics, makes this movie one of the last in which Freudian methods and conceptions (largely related to sex and childhood development) are shown to have a significant impact on the diagnosis of patients. With the rise of neurochemistry, neuroscience, and biological tests in the 1980s, 1990s and beyond, Freudian methods like those portrayed in the film would themselves become considered by many mainstream biological psychiatrists to be superstitious.