folie a deux
Noun: A rare psychiatric syndrome where a delusional belief or mental illness symptom is shared by two individuals in a close relationship, causing one person's psychotic symptoms to be induced in the other. It is characterized by the transfer of delusional ideas from a dominant, more ill individual (the "primary" or "inducer") to a more passive, suggestible partner (the "secondary" or "recipient").
The term is used in clinical psychology and psychiatry to diagnose a specific form of shared psychotic disorder. It describes a situation where the secondary individual's delusions are not self-generated but are adopted through a close, often isolated, relationship with the primary individual. - The psychiatrists diagnosed the reclusive sisters with folie à deux after they presented identical, elaborate paranoid delusions about government surveillance. - A classic case of folie à deux can sometimes develop in a marital relationship where one spouse's irrational jealousy is gradually accepted as reality by the other.
- The condition is formally classified in diagnostic manuals (e.g., DSM-5) under "Induced Delusional Disorder" or "Shared Psychotic Disorder."
- The phrase can be used metaphorically in non-clinical contexts to describe two people who jointly subscribe to an irrational or eccentric belief system, though this is an extended, figurative use.
- Critics accused the political duo of a kind of folie à deux, reinforcing each other's most extreme and unfounded conspiracy theories.
- Folie à famille: A rare extension where delusional beliefs are shared among several family members.
- Folie imposée: A specific subtype where the delusions are imposed by a dominant inducer on a more passive recipient, which then subside if the pair is separated.
- Shared psychotic disorder: The modern clinical term for the condition.
- Induced delusional disorder: An alternative clinical term.
- Shared psychosis
- Shared delusional disorder
- Psychosis by association (informal)
While not a phrasal verb, the term itself is a borrowed French phrase meaning "madness of two." Its use in English is fixed, and it is typically italicized or left in plain text without translation. - Their co-dependent relationship had all the hallmarks of a folie à deux.
- the simultaneous occurrence of symptoms of a mental disorder (as delusions) in two persons who are closely related (as siblings or man and wife)