Altered States is a 1980 American science fiction-horror film directed by Ken Russell, and adapted by playwright and screenwriter Paddy Chayefsky from his 1978 novel of the same name. The novel and the film are based in part on John C. Lilly's sensory deprivation research conducted in isolation tanks under the influence of psychoactive drugs like mescaline, ketamine, and LSD. The film features elements of both psychological horror and body horror.

Plot

In 1967, Edward Jessup is a Columbia University psychopathologist studying schizophrenia. He begins to think that "our other states of consciousness are as real as our waking states." He begins experimenting with sensory deprivation using a flotation tank, aided by two like-minded researchers, Arthur Rosenberg and Mason Parrish. At a faculty party, he meets fellow "whiz kid," and his future wife, Emily.