Urbach-Wiethe Disease

According to a 2010 report in the journal Current Biology, a woman known only as SM is literally fearless due to a rare genetic condition known as Urbach-Wiethe disease that hardened her amygdala, part of the brain responsible for fear response. Researchers exposed her to snakes, spiders, an amusement park haunted house and horror films, none of which scared her. Researchers said that these finding could help in progress for the treatment of post-traumatic stress disorders.