About the Project | The AFF Project. Folie à deux. Folie à deux (/fɒˈli ə ˈduː/; French pronunciation: [fɔli a dø]; 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.[1] 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 shared 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 by Charles Lasègue and Jean-Pierre Falret and so also known as Lasègue-Falret Syndrome.[2][3] Presentation[edit] This syndrome is most commonly diagnosed when the two or more individuals concerned live in proximity and may be socially or physically isolated and have little interaction with other people. SPACE COWBOY. Terra Nova.