"Reports of visitors to Jerusalem being seized by a religious psychosis date back to the Middle Ages. In the 1930s, Israeli psychiatrists formally described the condition in which tourists assume the persona of a Biblical character and make strange pronouncements at a holy site. (In one 1969 case, an Australian tourist set fire to a local mosque, sparking a citywide riot and a 1998 film of the same name.) An article in the British Journal of Psychiatry in 2000 noted that 1,200 patients had been referred to a central mental facility with the disorder between 1980 and 1993. Some had previous mental disorders; others seemed quite sane before and later resumed normal lives. The authors warned tour guides to be alert for the disorder's seven characteristic stages: Sufferers appear agitated; seek to leave the group to tour Jerusalem alone; become obsessed with purity and cleanliness; prepare a toga-like gown "often with the aid of hotel bed linen"; shout Bible verses, then march to a holy site and deliver a confused sermon that often appeals to humankind to adopt a more moral way of life."