Psyker

Psykers, commonly known to the public as Psychics, are an evolved subset of humanity, though sometimes classified as a supernatural species, whose members have developed potent paranormal abilities relating to the manipulation of the mind. These abilities can include seeing into the past/present/future, moving objects with their mind, summoning/binding ghosts, and reading minds. When first manifesting their abilities, they may experience severe headaches if they have precognitive abilities, such as Sam Winchester, or may experience only mild headaches after developing their abilities further, such as Ansem Weems.

Some psychics practice witchcraft to enhance or curtail their abilities but are not always classified as witches. By selling their soul to a demon (Borrowers) or by studying how to harness the forces of nature (Students), they become witches and gain the ability to extend their lifespan and gain more power/abilities. When Borrower Witches die, their deal is up and they are sent to Hell to be turned into a demon themselves, albeit with their psychic abilities further along then other hellbound souls, thus making them a particularly powerful demon when they turn after a few centuries of torture and damnation.

According to Gabriel Mikaelson, psykers develop any powers they will receive by the age of eighteen.

History
Psykers are a naturally occurring phenomenon dating back to the origins of humanity. The original humans appear to be the very first psychic beings on Earth, as both Adam, Arcadius, Lilith, Satrina, Cain, Abel, and Eve, all demonstrated vast psionic abilities, such as the warping of reality or extreme levels of telepathy and telekinesis. The ability seemed to be largely dormant in the majority of their descendants, with only a small handful exerting even a modicum of their talent. It is said that all of humanity contains the potential to develop psychic powers, allowing them to rise to equal terms with other supernatural beings.