The Church follows criterias in validating an alledged demonic possession. Some of them include: it is important to note that usually those who thinks that they're possessed aren't usually 'possessed'. They usually have other problems (psychologically,emotionally or they just want attention). Usually, those who are really possessed thinks that their problems are not of demonic origin. Only later on will they found out otherwise. All medical causes in such case should have been ruled out and that all medical treatment has been exhausted but caused no relief or positive response to the victim. If the cause is demonic, then medical treatment is of little/no help. Another is aversion of the sacred or extreme hatred of sacred signs/symbol like crucifixes, holy water, the bible, etc. The priest may bless a water unknown to the allegedly possessed and ask him to drink it. If the person hates the water so much then it is a possibility that the person is possessed. To verify the hoax from the genuine, exorcists also do some simple tests. Like reading a literature written in Latin (here, the priest pretend that he's reading prayers from the Latin version of the rite while the fact is he's not. Once the patient reacts negatively then it's a fake one. If that happens,the person is usually referred to a psychiatrist or psychologist. If there really is a demon possessing that person then it would show no reaction or mock that act. Another possible sign is the knowledge of the unknowable. He/she knows unknown events in the past or knows things that are"secret" Possessed usually has knowledge of hidden things. The exorcist can diagnose that by putting an object in a sealed container or a bag for example without the knowledge of the person and asks him/her to guess what's inside. If a demon operates truly in a person, he/she would know what:s inside.