Psychiatry and Possession

Is it possible to be a sophisticated psychiatrist and believe that evil spirits are, however seldom, assailing humans? Most of my scientific colleagues and friends say no, because of their frequent contact with patients who are deluded about demons, their general skepticism of the supernatural, and their commitment to employ only standard, peer-reviewed treatments that do not potentially mislead (a definite risk) or harm vulnerable patients. But careful observation of the evidence presented to me in my career has led me to believe that certain extremely uncommon cases can be explained no other way.