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 Christianity
In general, people considered to be possessed are not regarded as evil in themselves, nor wholly responsible for their actions, because possession is considered to be unwilling manipulation by a demon resulting in harm to self or others. Therefore, practitioners regard exorcism as more of a cure than a punishment. The mainstream rituals usually take this into account, making sure that there is no violence to the possessed, only that they be tied down if there is potential for violence.