Etymologically meaning "mind manifesting," a psychedelic experience is characterized by hallucinations, distortions of perception, altered states of awareness, mystical states, and occasionally states resembling psychosis. Modern proponents of psychedelics do not define psychedelics based on their hallucinatory effects, but more often on their mental effects.
The use of psychedelic drugs became widespread in the mid-1960s. Timothy Leary was a well known proponent of their use, as was Aldous Huxley. The fashion for psychedelic drugs gave its name to the visual style of psychedelia, and to a rock music style that became known as psychedelic music.