An entheogen (/en·the·o·gen/), from Greek, literally meaning "generating the divine within", is any psychoactive substance that induces a spiritual experience and is aimed at spiritual development. This terminology is often chosen to contrast with recreational use of the same drugs.
Most entheogens are hallucinogens, although some are mood-altering substances. A common long-term goal with entheogens for shamans is to being able to achieve altered states of consciousness in sober condition so they don't need them any more. A healthy set and setting plays a vital role to avoid a bad trip which may trigger a latent mental illness to become severe.
The religious, shamanic, or spiritual significance of entheogens is well established in anthropological and modern contexts; entheogens have traditionally been used to supplement many diverse practices geared towards achieving transcendence, including sensory deprivation, divinatory, meditation, yoga, prayer, trance, chanting, hymns like peyote songs, and drumming. The use of entheogens was kept secret by native societies to the Western world until the 1950s, which quickly developed into psychedelic therapy. Later clinical trials have shown that these substances have helped people with such mental disorders as OCD, PTSD, alcoholism, depression, and cluster headaches. In the 1960s the hippie movement escalated its use to psychedelic art and binaural beats, sensory deprivation tank, music, and on rave parties.