Tags: Disease.
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. 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).