In A Nutshell
In 1999, the Vatican revised its guidelines for both performing exorcisms and determining whether a person was actually suffering from a demonic possession or from a form of mental illness. Priests now consult with mental health professionals when assessing a person’s affliction. In order to be declared possessed by a demon, priests look for the ability to speak in foreign tongues previously unknown to the person as well as strength that the person should not be capable of demonstrating, as well as eliminating all other possible causes for the distress.
The Whole Bushel
The performing of exorcisms has been an important part of the Catholic Church for centuries. The practice dates back to the Bible and the stories that are told about Jesus Christ vanquishing the demons who possessed the body of various people. Afterward, he transferred his powers of exorcism to the Apostles. In turn, the priesthood of the Catholic Church is also said to possess powers of exorcism.
In 1999, the Vatican issued an official revision of the guidelines for both performing an exorcism and determining whether or not one needed to be performed at all. In the first revision since 1614, it was the guidelines for determining whether or not a person is possessed that underwent the most change.
Now, the Catholic Church is careful to discern between what they consider to be actual possession by a demonic entity and the manifestation of mental illness. No longer do they simply decide that a person who flinches at the sight of a crucifix is possessed.
Updated rules for declaring someone possessed by demons include consulting with medical and psychiatric professionals to rule out any physical cause for the person’s distress as well as to explore possibilities of the manifestation of mental illness before a diagnosis of demonic possession is even considered.
The things that a priest will look for are things that can’t easily be faked, such as fluently speaking in a language that was previously unknown to the person, and demonstrating an inappropriate strength. According to the church, an afflicted person’s ability to know things that they absolutely should have no knowledge of—such as personal information about the priests and professionals performing the inquiry—is also a sign that they’re dealing with an actual demonic possession.
Also very, very clear in Vatican guidelines is the idea that all of the above criteria can also be faked; although more difficult, they acknowledge that it’s possible and stress the importance of ruling out all other possibilities first.
Previously, it was quite easy for a person to demonstrate symptoms of demonic possession but be suffering from something completely different—or, from nothing at all. At one point, aggression, cursing, self-inflicted injuries, and a demonstrated hatred of religious objects were all considered signs that a person was certainly suffering from what’s now called “genuine possession.” Guidelines like the more recently established speaking in unknown languages were established to help priests and counselors alike differentiate between genuine possession and pseudo-possession: that is, the appearance of symptoms in a person suffering from a mental illness, often schizophrenia and other dissociative disorders.
The Catholic Church has also included in their established guidelines that those individuals who believe they are suffering from a curse or similar affliction are not to undergo an exorcism. Both the church and the medical profession draw the line between demonic evil and human evil, and acknowledge that in some cases, especially in those cases where the afflicted is a true believer, the symptoms can be difficult to sort out.
Much of the doctrine on exorcism has remained unchanged for centuries, including the basis of what it actually entails. The church counts it of the utmost importance that it is not the mind of an individual that is possessed by the demons, but the body, putting the mind in a sort of suspended state while the demon takes control of the body. Fundamentally, the church’s description of what’s happening during a demonic possession is quite different from the psychological issues that develop when a person suffers from mental illness.
Show Me The Proof
Catholic Education Resource Center: Demonic Possession Involves Body, Not Soul
The Guardian: Vatican lays down new rules for exorcism
Exorcism! Driving Out the Nonsense
Psychology Today: Exorcism as Psychotherapy: A Clinical Psychologist Examines So-Called Demonic Possession