In psychology, Folie à deux  is a rare psychiatric phenomenon where delusional beliefs are shared between two people, usually related. It’s French for “a madness shared by two.” This week we’re looking at the case of Ursula and Sabina Eriksson, two Swedish twins who are believed to be a perfect example of the frightening illness. The had no history of delinquency or mental illness, so why then, did they embark on a suicide mission by running down the M6 Motorway into oncoming traffic? These twins went on this one day bender in 2008 and have not been seen or heard from since. 

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