Altered States

Altered States is a 1980 American science fictionhorror film adaptation of a novel by the same name by playwright and screenwriter Paddy Chayefsky. Altered States was Chayefskys only novel and his final screenplay. Both the novel and the film are based on John C. Lillys sensory deprivation research conducted in isolation tanks under the influence of psychoactive drugs like mescaline, ketamine and LSD.

Edward Jessup is a university professor of abnormal psychology who, while studying schizophrenia, begins to think that our other states of consciousness are as real as our waking states. Jessup begins experimenting with sensory deprivation using a flotation tank, aided by two likeminded researchers, Parrish and Rosenberg. At a faculty party he meets fellow wonder kid Emily and the two eventually marry.When Edward hears of a Mexican tribe that experiences shared illusion states, he travels to Mexico to participate in what is apparently an Ayahuasca Ceremony. During the walk into the bush his guide states that the indigenous tribe they are meeting works with Amanita muscaria which they are collecting for next years ceremonies. An indigenous elder is seen with Banisteriopsis caapi root in his hand prior to cutting Jessups hand, adding blood to the mixture he is preparing. Immediately after consumption Edward experiences bizarre, intense imagery. He returns to the U.S. with a tincture and begins taking it orally before each session in the flotation tank where he experiences a series of increasingly drastic psychological and physical transformations. ........

Source: Wikipedia