Folie a deux is seen in :

B i.e. Paranoid Induced Delusional Disorder Characterized by sharing of delusions between usually two (Folie a deux)Q or rarely more (Folie a trois, Folic a quatre, Folie a famille) persons who usually have closely Knit emotional bond. Only one person has genuine delusions due to an underlying psychiatric disorder. On separation, dependant individual may give up their delusions and patient with genuine delusions: should be' treated according to underlying disease.