What is a Psychedelic?

A psychedelic is a substance—be it a plant, mushroom, extract, powder, or chemical molecule—that, when consumed, induces a non-ordinary state of consciousness. This psychedelic experience is typically distinct from those produced by other psychoactive substances, manifesting in pronounced changes in perception, mood, and cognitive processes, as well as being virtually nonaddictive.

The term 'psychedelic' was coined in 1956 by psychiatrist Humphrey Osmond (while working at the Weyburn Mental Hospital, in Saskatchewan) during correspondence with writer and philosopher Aldous Huxley. Derived from the Greek words psychḗ, meaning 'life-soul' or 'mind,' and dēleín, meaning 'to manifest' or 'to reveal,' the term essentially signifies 'to reveal the (life)soul' or 'to reveal the mind,' depending on the interpretation of 'psyche.'

Aldous Huxley had previously suggested 'phanerothyme', derived from the Greek words, phaneroein meaning 'to make manifest or visible', and thymos meaning 'breath-soul', thus 'to reveal the (breath)soul', but Osmond's psychedelic proved to be far more popular (and easier to remember).

Due to the cultural associations of the term 'psychedelic' with the late 1960s and early 1970s, and the perception of psychedelics as potent facilitators of transformative spiritual experiences, the term 'entheogen' was proposed in 1979. Derived from the Greek words, éntheos meaning 'full of the god, inspired, possessed', and genésthai meaning 'to come into being', thus to 'bring godly inspiration into being', or to 'generate the divine within'. It is often used to describe substances with a longstanding ceremonial tradition, and can include substances which would not typically be considered to be psychedelics, such as tobacco, datura, or cannabis.

The most well known or “classic psychedelics”, are LSD, mescaline, and psilocybin containing mushrooms.

Some other entheogens are also considered to be psychedelics such as morning glory seeds, Ayahuasca, and Iboga.

Also included are a vast range of various tryptamines, phenethylamines, and lysergamides, including NN-DMT, 5-MeO-DMT, 4-ACO-DMT, and 2C-B.

Although commonly mentioned when discussing psychedelics, and also commonly used in psychedelic therapy, neither MDMA (which is an empathogen and/or entactogen), nor ketamine (a dissociative anesthetic) are actually classified as psychedelics.