Ken Russell's 1980 film Altered States was adapted from the only novel written by Paddy Chayefsky. Both the film and source novel reference/"borrow" John C. Lilly's research into sensory deprivation and the influence of psychoactive drugs on those involved while inside isolation tanks. Even though the film's special effects have not aged well and it tends to get bogged down in pretentiousness at times, some of the visuals are suitably hallucinatory. This was William Hurt's screen debut.
the trailer
the feature