The term "psychedelic" is derived from the Ancient Greek words "psyche" (meaning "mind") and "delos" (which means "to manifest"), coined by a psychiatrist named Humphrey Osmond in a letter sent to the famous author Aldous Huxley in 1956. Writing about the merits and pitfalls of LSD and mescaline, Osmond came up with the rhyming couplet: “to fathom hell or soar angelic, just take a pinch of psychedelic.”
By this, he meant that certain substances have the potential to expose and activate hidden layers of consciousness, triggering experiences that can range from the diabolical to the sublime. Over half a century later, scientists are finally putting psychedelics under the microscope in an attempt to reveal how they generate these surreal phrenic odysseys.
Losing the Self
Poetic though they may be, outcomes like fathoming hell or soaring angelic are difficult to define scientifically. This is why researchers have developed a tool called the Five-Dimensional Altered States of Consciousness (5D-ASC) Rating Scale to help categorize psychedelic experiences. The scale measures aspects such as “oceanic boundlessness”, a feeling of being indistinct from one’s surroundings, plus a more general loss of the sense of self, referred to as “ego-dissolution”.
Exactly how a psychedelic “pinch” transports one’s consciousness down the 5D-ASC rabbit hole is not yet fully understood, although we do know that it all hinges on a particular type of serotonin receptor called 5-HT2A. Numerous studies have revealed that psychedelics like LSD, psilocybin, and ayahuasca exert their mind-altering effects by activating this receptor, and chemically blocking 5-HT2A binding sites appears to nullify the potency of these substances.
For instance, one study found that giving people LSD caused a blurring of the perceived boundaries between themselves and others, but that this could be avoided by deactivating their 5-HT2A receptors using a compound called ketanserin. Dr Matthew Jonson, professor of psychiatry and behavioral sciences at Johns Hopkins University, told IFLScience that this sense of ego-dissolution is a hallmark of “mystical experiences”, which some researchers believe are key to the healing potential of psychedelics.
“The real tell-tale, or at least the most impressive feature of a mystical experience, is having this notion of oneness where the sense of subject and object break down,” he said. One of the world’s most published scientists on the effects of psychedelics, Johnson went on to explain that this phenomenon occurs when psychedelic drugs “loosen the self-narrative” by temporarily disrupting the neurological blueprint for one’s own identity.
An archetypal reaction to psychedelic drugs, mystical experiences are categorized using the Mystical Experience Questionnaire (MEQ), which measures such things as a “feeling that you experienced eternity or infinity” and “the insight that 'all is One'.” How one little receptor can generate such grandiose shifts in consciousness is something that researchers are slowly beginning to understand.