Exorcism
In Catholic Christianity, exorcisms are performed in the name of Jesus Christ. A distinction is made between a formal exorcism, which can only be conducted by a priest during a baptism or with the permission of a bishop, and "prayers of deliverance" which can be said by anyone.
The Catholic rite for a formal exorcism, called a "Major Exorcism", is given in Section 11 of the Rituale Romanum. The Ritual lists guidelines for conducting an exorcism, and for determining when a formal exorcism is required. Priests are instructed to carefully determine that the nature of the affliction is not actually a psychological or physical illness before proceeding.
Thomas Bermingham (priest)
"The Exorcist" is a 1973 supernatural horror film by William Peter Blatty, based on the true story of Roland Doe, a 1949 case in which Catholic priests performed a series of exorcisms on a 14-year-old boy in Maryland.