Altered States | 1980
A professor in abnormal psychology who is studying schizophrenia develops a theory that other states of consciousness are as real as the waking state. He begins experimenting using sensory-deprivation and drugs on himself. This experimentation leads to extreme psychological and physical changes, at one point transforming him into a primitive man, and escalating until he is finally regressed into a mass of primordial matter. His wife intervenes before the professor de-evolves into a state of non-being, and he returns to his original, human form.