Interesting facts:
• Folie à deux is a rare 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").
• Being defined as a rare pathological manifestation, folie à deux is rarely found in general psychology or social psychology text books, and is relatively unknown outside abnormal psychology, psychiatry, and psychopathology.
• Folie à deux or even folie à plusieurs have been reported during Shamanic journeying in a group setting. A typical example is that of the interaction between power animals of two or more people who were guided in a Power-Animal retrieval journey during the same session and by the same Shaman.