Altered States is a 1980 American science fiction-horror film adaptation of a novel by the same name by playwright and screenwriter Paddy Chayefsky in his only novel he ever wrote and his final film. Both the novel and the film are based 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 was directed by Ken Russell and is also the film debut of William Hurt and Drew Barrymore.