Incredibly fascinating.Ursula and Sabina Eriksson, born 1967, are a pair of Swedish twins who came to national attention in the United Kingdom in 2008 after an apparent episode of folie à deux, which resulted in unique footage of insanity on the M6 motorway, and the killing of Glenn Hollinshead. No drugs or alcohol were involved in any of the incidents. Their actions have never been explained, other than by a rare induced delusional disorder which caused the pair to be temporarily insane.
The twins met up in Ireland, before travelling to England. After their odd behaviour caused them to be left at an M6 service station, they ran on to the motorway numerous times, and were struck by oncoming vehicles, causing Ursula to be incapacitated. Sabina refused medical aid and attacked a police officer, at which point she was arrested. After being released by police in Stoke-on-Trent, Sabina then was taken in by a local resident, whom she later killed in an unprovoked attack. After jumping off a bridge into a busy road she was arrested, and later pleaded guilty to manslaughter with diminished responsibility. She was sentenced to five years imprisonment. The trial had virtually no legal precedence.
http://en.wikipedia.org/wiki/Ursula_and_Sabina_Eriksson
Folie à deux from the French for "a madness shared by two") (or shared psychosis) is a psychiatric syndrome in which symptoms of a delusional belief are transmitted from one individual to another. The same syndrome shared by more than two people may be called folie à trois, folie à quatre, folie en famille or even folie à plusieurs ("madness of many"). Recent psychiatric classifications refer to the syndrome as dependency psychotic disorder (DSM-IV) (297.3) and induced delusional disorder (F.24) in the ICD-10, although the research literature largely uses the original name. The disorder was first conceptualized in 19th century French psychiatry
http://en.wikipedia.org/wiki/Folie_%C3%A0_deux
