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 13 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 medical illness before proceeding.
In Christian practice the person performing the exorcism, known as an exorcist, is often a member of the church, or an individual thought to be graced with special powers or skills. The exorcist may use prayers, and religious material, such as set formulas, gestures, symbols, icons, amulets, etc. The exorcist often invokes God, Jesus, a litany of saints, and/or several different angels and archangels to intervene with the exorcism. It may take several weekly exorcisms over several years to expel a deeply entrenched demon.
In general, possessed persons are not regarded as evil in themselves, nor wholly responsible for their actions. 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 deemed necessary for their own protection and that of the practitioner.
Beliefs and practices pertaining to the practice of exorcism are prominently connected with Hindus. Of the four Vedas (holy books of the Hindus), the Atharva Veda is said to contain the secrets related to magic and alchemy. The basic means of exorcism are the mantra and the yajna used in both Vedic and Tantric traditions. Vaishnava traditions also employ a recitation of names of Narasimha and reading scriptures, notably the Bhagavata Purana aloud. According to Gita Mahatmya of Padma Purana, reading the 3rd, 7th and 8th chapter of Bhagavad Gita and mentally offering the result to departed persons helps them to get released from their ghostly situation. Kirtan, continuous playing of mantras, keeping scriptures and holy pictures of the deities (Shiva, Vishnu, Brahma, Shakti, etc.) (especially of Narasimha) in the house, burning incense offered during a Puja, sprinkling water from holy rivers, and blowing conches used in puja are other effective practices.
The main puranic resource on ghost and death-related information is Garuda Purana.
In Islam, exorcism is called ruqya. It is used to repair the damage caused by sihr or witchcraft. It consists of reciting some specific verses from the Quran which glorify God (e.g. The Throne Verse (Arabic: آية الكرسي Ayatul Kursi), and invoke God's help. In some cases, the adhan (the call for daily prayers) is also read, as this has the effect of repelling non-angelic unseen beings or the jinn.
The Islamic prophet Muhammad taught his followers to read the last three suras from the Quran, Surat al-Ikhlas (The Fidelity), Surat al-Falaq (The Dawn) and Surat al-Nas (Mankind).
Josephus reports exorcisms performed by administering poisonous root extracts and others by making sacrifices. The Dead Sea Scrolls mention that exorcisms were done by the Essene branch of Judaism.
In more recent times, Rabbi Yehuda Fetaya authored the book Minchat Yahuda, which deals extensively with exorcism, his experience with possessed people, and other subjects of Jewish thought. The book is written in Hebrew and was translated into English.
Rabbi Gershon Winkler of New Mexico explains that the procedure for a Jewish exorcism is intended not only to drive away the possessing force, but to help both the possessor and the possessed in an act of healing. The Jewish exorcism ritual is performed by a rabbi who has mastered practical Kabbalah. Also present is a minyan (a group of ten adult males), who gather in a circle around the possessed person. The group recites Psalm 91 three times, and then the rabbi blows a shofar (a ram's horn). The shofar is blown in a certain way, with various notes and tones, in effect to "shatter the body" so that the possessing force will be shaken loose. After it has been shaken loose, the rabbi begins to communicate with it and ask it questions such as why it is possessing the body of the possessed. The minyan may pray for it and perform a ceremony for it in order to enable it to feel safe, and so that it can leave the person's body.
Demonic possession is not a valid psychiatric or medical diagnosis recognized by either the DSM-IV or the ICD-10. Those who profess a belief in demonic possession have sometimes ascribed the symptoms associated with mental illnesses, such as hysteria, mania, psychosis, Tourette's syndrome, epilepsy, schizophrenia or dissociative identity disorder, to possession. In cases of dissociative identity disorder in which the alter personality is questioned as to its identity, 29% are reported to identify themselves as demons. Additionally, there is a form of monomania called demonomania or demonopathy in which the patient believes that he or she is possessed by one or more demons.
The illusion that exorcism works on people experiencing symptoms of possession is attributed by some to placebo effect and the power of suggestion. Some supposedly possessed persons are actually narcissists or are suffering from low self-esteem and act like a "demon possessed person" in order to gain attention.
Psychiatrist M. Scott Peck researched exorcisms and claimed to have conducted two himself. He concluded that the Christian concept of possession was a genuine phenomenon. He derived diagnostic criteria somewhat different from those used by the Roman Catholic Church. He also claimed to see differences in exorcism procedures and progression. After his experiences, and in an attempt to get his research validated, he attempted but failed to get the psychiatric community to add the definition of "Evil" to the DSM-IV. Although Peck's earlier work was met with widespread popular acceptance, his work on the topics of evil and possession generated significant debate and derision. Much was made of his association with (and admiration for) the controversial Malachi Martin, a Roman Catholic priest and a former Jesuit, despite the fact that Peck consistently called Martin a liar and manipulator. Other criticisms leveled against Peck included misdiagnoses based upon a lack of knowledge regarding dissociative identity disorder (formerly known as multiple personality disorder), and claims that he had transgressed the boundaries of professional ethics by attempting to persuade his patients to accept Christianity.