folie a deux: meaning, definition, pronunciation and examples
C2formal, technical, literary
Quick answer
What does “folie a deux” mean?
A psychiatric syndrome in which symptoms of a mental disorder, particularly delusional beliefs or hallucinations, are shared by two or more closely associated people.
Audio
Pronunciation
Definition
Meaning and Definition
A psychiatric syndrome in which symptoms of a mental disorder, particularly delusional beliefs or hallucinations, are shared by two or more closely associated people.
Any shared delusion, obsession, or irrational belief system held by two or more people, often used metaphorically in non-clinical contexts.
Dialectal Variation
British vs American Usage
Differences
No significant orthographic or definitional differences. Both use the French spelling with diacritics (though sometimes anglicised to 'folie a deux').
Connotations
In both, retains a strong clinical/academic flavour, but metaphorical use is common. In metaphorical use, it can carry a slightly humorous or ironic tone.
Frequency
Equally low-frequency in both varieties, confined to educated/formal registers. Slightly more common in American psychology/psychiatry literature due to its inclusion in DSM.
Grammar
How to Use “folie a deux” in a Sentence
[subject] was a classic folie à deux.They suffered from a shared folie à deux.Their relationship descended into a kind of folie à deux.Vocabulary
Collocations
Examples
Examples of “folie a deux” in a Sentence
verb
British English
- N/A – not used as a verb
American English
- N/A – not used as a verb
adverb
British English
- N/A
American English
- N/A
adjective
British English
- N/A – not used as a standard adjective. Attributive use: 'a folie-à-deux dynamic'.
American English
- N/A – not used as a standard adjective. Attributive use: 'a folie-à-deux relationship'.
Usage
Meaning in Context
Business
Rare. Used metaphorically for two leaders sharing a disastrous, out-of-touch business vision. 'The CEO and CFO were locked in a folie à deux about the company's invincibility.'
Academic
Common in psychology, psychiatry, sociology, and literary criticism to analyse relationships and shared beliefs.
Everyday
Very rare. If used, it's metaphorical, often in educated conversation about relationships or politics. 'Their obsession with that diet is a folie à deux.'
Technical
Standard term in clinical psychiatry (DSM-5: 'Induced Delusional Disorder'). Describes a specific syndrome.
Vocabulary
Synonyms of “folie a deux”
Strong
Neutral
Weak
Vocabulary
Antonyms of “folie a deux”
Watch out
Common Mistakes When Using “folie a deux”
- Misspelling: 'folie a deux' (missing accent), 'folie a du', 'folly a deux'.
- Mispronouncing 'deux' as /djuːks/ or /deks/.
- Using it to describe any disagreement or conflict (it's about shared, not opposing, beliefs).
- Applying it to large groups (it's specifically for two, or sometimes a very small group: folie à trois).
FAQ
Frequently Asked Questions
It is standard to italicise it in formal writing as it is a foreign term not fully anglicised, though in psychology texts it is often in roman type.
Yes, the concept extends to 'folie à trois', 'folie à famille', or 'folie à plusieurs', but 'folie à deux' remains the most common term.
No. The key difference is in 'deux'. British English uses /ˈdɜː/ (like 'durr'), while American English uses /ˈduː/ (like 'do').
No, it is a low-frequency, specialised term. You will encounter it mainly in academic, clinical, or sophisticated journalistic contexts, often used metaphorically.
A psychiatric syndrome in which symptoms of a mental disorder, particularly delusional beliefs or hallucinations, are shared by two or more closely associated people.
Folie a deux is usually formal, technical, literary in register.
Phrases
Idioms & Phrases
- “Their conspiracy theories were a folie à deux.”
Learning
Memory Aids
Mnemonic
Think: 'FOLLY (folie) for TWO (à deux)' – a shared foolishness.
Conceptual Metaphor
IDEAS ARE DISEASES (shared delusion as a contagious illness). RELATIONSHIPS ARE CONTAINERS (the pair is sealed in a bubble of madness).
Practice
Quiz
In which field did the term 'folie à deux' originate?