Research conducted at the University of California, San Diego and published in the British Medical Journal, suggests that deaths attributed to heart mortality increase under psychological stress, particularly terror.[5] Otherwise healthy people have been known to be "scared to death," that is, to suddenly die under extreme fear or emotional trauma. People of all ages have died from fright brought on by everything from earthquakes to amusement-park rides.[6][7]

While the mechanism is not fully understood, it is believed that sudden death can occur from cardiac arrhythmia brought on by a terrifying event.[6] While the otherwise instinctual flight-or-fight response, which prepares the body for impending danger, is countered by the parasympathetic nervous system when the danger has passed, in certain cases an excessive response can damage the heart enough to kill