folie a deux

Last reviewed 01/2018

Folie a deux is the situation where a paranoid delusional system appears to have developed in a person as a result of a close relationship with another person who has an established and similar delusional system.

This condition is rare and is usually seen in two people who are members of the same family. Generally there is a dominant partner with fixed delusions who appears to induce similar delusions in a dependent or suggestible partner. This sometimes will occur after initial resistance. Usually the two people have lived together for a long time in close intimacy. There is often isolation from the outside world.

The delusions of the second person quickly weaken if the two are separated.