folie à deux

English Wikipedia has an article on:

folie à deux

Wikipedia

• folie a deux (without diacritics)
• folly à deux, folly a deux (rare)

Borrowed from French folie à deux (“madness for/of two ”).

• IPA^(key): /ˈfɒli ə ˈdɜː/

folie à deux (plural folies à deux)

1. A situation in which two people behave abnormally together in a way that neither of them would on their own.
2. (psychiatry, strictly) A rare syndrome in which a symptom of psychosis (particularly a paranoid or delusional belief) is transmitted from one person to another.

• à deux
• folie à trois

• IPA^(key): /fɔ.li a dø/

folie à deux f (plural folies à deux)

1. folie à deux

Swedish Wikipedia has an article on:

folie à deux

Wikipedia ^sv

Unadapted borrowing from French folie à deux.

folie à deux c

1. (uncommon) folie à deux
   • 1997, Ola Hansson, Ulf Linde, “Mullens outsider”, in Ingvar Holm, editor, Lyrik och essäer, page IX:

     Men paret Hansson blev alltmer besynnerligt och i april 1905 hade deras gemensamt utvecklade förföljelseidéer, ett slags folie à deux, tagit sådana proportioner att en katastrof var oundvikligt.

     But the Hansson couple became increasingly peculiar, and by April 1905, their jointly developed delusions of persecution, a kind of folie à deux, had grown to such proportions that a catastrophe was inevitable.

   • 2009 August 8, Kerstin Nilsson, “Tvingades döda för att visa sin kärlek [Forced to kill to prove their love]”, in Aftonbladet (column):

     Jag hittar ingenting som jag vill kalla kärlek, varken i de över flera hundra sidor långa förhören eller den långa listan med alla sms. Beroende, ja. Besatthet, ja. Svartsjuka, ja. Kontrollbehov, ja. Men kärlek, nej. Snarare ett slags ”folie à deux” – en galenskap på två. Hur kunde det gå så överstyr?

     I find nothing that I would call love, neither in the interrogations spanning hundreds of pages nor in the long list of all the text messages. Dependency, yes. Obsession, yes. Jealousy, yes. Need for control, yes. But love, no. Rather a kind of "folie à deux" – a madness shared by two. How could it get so out of hand?

   • 2019 September 7, Magnus Ringgren, “Man sugs in i deras besatthet [One is drawn into their obsession]”, in Aftonbladet (poetry review):

     Vi har sett det förr i konsten och i verkligheten – en gammal term för det här är folie à deux. Denna dubbelgalenskap är en lika fruktbar som giftig jordmån.

     We have seen it before in art and in reality – an old term for this is folie à deux. This shared madness is a ground that is as fertile as it is toxic.

• inducerat vanföreställningssyndrom (“induced delusional disorder”)
• symbiogen psykos (“symbiogenic psychosis”)