"Dimethyltryptamine (DMT), is a naturally occurring potent psychedelic drug, found not only in many plants, but also in trace amounts in the human body wherein its natural function is undetermined. Structurally, it is analogous to the neurotransmitter serotonin. In the central nervous system, serotonin plays an important role as a neurotransmitter in the modulation of anger, aggression, body temperature, mood, sleep, sexuality, appetite, and metabolism.
Several speculative and as yet untested hypotheses suggest that endogenous DMT, produced in the human brain, is involved in certain psychological and neurological states. As DMT is naturally produced in small amounts in the brains and other tissues of humans, and other mammals, some believe it plays a role in promoting the visual effects of natural dreaming, and also near death experiences and other mystical states. A biochemical mechanism for this was proposed by the medical researcher J.C Callaway, who suggested in 1988 that DMT might be connected with visual dream phenomena, where brain DMT levels are periodically elevated to induce visual dreaming and possibly other natural states of mind.
Writers on DMT include Terence McKenna. Though most scientists who study psychedelic drugs treat their writings with skepticism. McKenna writes of his DMT experiences with a decidedly less skeptical slant, often presuming that the drug's "intoxication" is indicative of realms of consciousness equally as valid as waking-life if not moreso.

DMT is classified in the United Kingdom as a Class A drug."