Folie à Deux
A rare psychiatric occurrence in which one person’s psychotic symptom(s), such as delusions, are transmitted to another person. Literally means “madness shared by two” in French; the disorder is also known as shared psychotic disorder.
Example: A woman and her eight-year-old daughter both believe that Satan lives in their basement. Treatment of the mother cures the daughter.
Grinnell, R. (2008). Folie à Deux. Psych Central. Retrieved on November 30, 2015, from http://psychcentral.com/encyclopedia/2008/folie-a-deux/