Spirit possession is the paranormal/supernatural event in which, allegedly, spirits, gods, demons, animas, extraterrestrials, or other disincarnate or extraterrestrial entities take control of a human body, resulting in noticeable changes in health and behaviour. The term can also describe a similar action of taking residence in an inanimate object, possibly giving it animation. The concept of spiritual possession exists in many religions, including Islam, Christianity, Buddhism, Haitian Voodoo, Wicca, and Southeast Asian and African traditions. Possession may be voluntary or involuntary and may be considered to have beneficial or detrimental effects.
Those who profess a belief in demonic possession have sometimes ascribed symptoms similar to those associated with mental illnesses such as psychosis, hysteria, mania, Tourette's syndrome, epilepsy, schizophrenia or dissociative identity disorder. A constant feature of possession is involuntary, uncensored behavior, and an extra-human, extra-social aspect to the individual's actions. He is dehumanized, bereft of normal powers of recognition and reaction, and his speech and movements are distant from the societal norm. In the cases of animal possession, the individuals deportment suggests that of an animal.