One of the results of possession by evil spirits in the maniac of Gadara was self-mutilation. Mark 5:5And always, night and day, he was in the mountains, and in the tombs, crying, and cutting himself with stones.
See All... describes his actions: "And always, night and day, he was in the mountains, and in the tombs, crying, and cutting himself with stones." A recent survey of college students has determined that 20% of women and 14% of men "have cut, burned, carved or harmed themselves in other ways." This refers to behavior which inflicts harm without the intent of suicide. "The most common methods reported by both young men and women were scratching to the point of bleeding, cutting or punching with the intent of causing injury." This is not to say that all of these young people are possessed. However, it does reflect on the satanic influence in our society. In the case of the maniac, when the devils were cast out, he was found "sitting at the feet of Jesus, clothed, and in his right mind" (Luke 8:35Then they went out to see what was done; and came to Jesus, and found the man, out of whom the devils were departed, sitting at the feet of Jesus, clothed, and in his right mind: and they were afraid.
See All...). We need to be taking our youth to the feet of Jesus instead of immersing them in the culture of the devil.

http://www.sciencedaily.com/releases/2006/06/060605155351.htm