Shared psychotic disorder (Folie a deux) is an unusual mental disorder characterized by sharing a delusion among two or more people who are in a close relationship. The (inducer, primary) who has a psychotic disorder with delusions influences another individual or more (induced, secondary) with a specific belief. It commonly presents among two individuals, but in rare cases can include larger groups, i.e., family and called folie a famille.

1. Srivastava A, Borkar HA. Folie a famille. Indian J Psychiatry. 2010 Jan;52(1):69-70