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.
Exorcism
In the UK, exorcisms are increasing. They happen mainly in charismatic and Pentecostal churches, and also among communities of West African origin. Frequently, the people exorcised are mentally disturbed. Mentally ill people are sometimes told to stop their medication as the church believes prayer and/or exorcism is enough. If psychiatric patients do not get better after exorcism, they may believe they have failed to overcome the demon and get worse.