Tourette's syndrome confused with demonic possession

Davidson, 34, has an extreme form of Tourette syndrome, a neurological condition characterised by involuntary, repetitive movements and vocal outbursts. It leads him to swear and shout offensive comments. His life story sounds like a throwback to the Middle Ages. There was an attempted exorcism by religious fanatics dressed in white and carrying crucifixes. He has been attacked with bricks and crowbars. As a teenager, his doctor prescribed Valium injections every three hours, which turned him into a virtual zombie. Teachers took to shutting him in cupboards. Even now, he is regularly ejected from buses and trains.