Folie à deux

Folie à deux
Synonyms	Shared psychotic disorder, shared delusional disorder
Pronounce	N/A
Specialty	N/A
Symptoms	Delusions shared between two or more individuals
Complications	N/A
Onset	Variable
Duration	Variable
Types	N/A
Causes	Close relationship with a person who has a psychotic disorder
Risks	Social isolation, stress, mental illness
Diagnosis	Clinical evaluation
Differential diagnosis	Schizophrenia, bipolar disorder, delusional disorder
Prevention	N/A
Treatment	Separation of individuals, antipsychotics, psychotherapy
Medication	N/A
Prognosis	Generally good with treatment
Frequency	Rare
Deaths	N/A

Main article: Folie à deux

Also called induced psychosis, folie à deux is a delusional disorder shared by two or more people who are closely related emotionally. One has real psychosis while the symptoms of psychosis are induced in the other or others due to close attachment to the one with psychosis. Separation usually results in symptomatic improvement in the one who is not psychotic. Folie communiquée, folie imposée, folie induite, and folie simultanée are the four subtypes of folie à deux.

Folie communiquée

Folie communiquée, or subtype C of folie à deux, occurs when a normal person suffers a contagion of his ideas after resisting them for a long time. Once he acquires these beliefs he maintains them despite separation.

Folie imposée

Folie imposée, or subtype A of folie a deux, is the most common form in which the dominant person imposes a delusion into a person who was not previously mentally ill. Separation of the two results in improvement of the non-dominant person.

Folie induite

In folie induite, or subtype D of folie a deux, a person who is already psychotic adds the delusions of a closely associated person to his own.

Folie simultanée

In folie simultanée, or subtype B of folie a deux, a delusional system emerges simultaneously and independently in two closely related persons, and the separation of the two would not be beneficial in the resolution of psychopathology.