folie à deux
/ˌfɒlɪ a ˈdəː
/noun (plural folies à deux) [mass noun]
Delusion or mental illness shared by two people in close association: a classic case of folie à deux [count noun]: she entered a folie à deux with her therapist...
- They each reinforce each others insanity - in psychology this is called a folie à deux or a shared madness.
- As noted above, we could uncover no causative or precipitating emotional or other factors for this folie à deux dissociative disorder.
- Addicts of flaming folies à deux will be pleased to learn that this season is providing a promisingly thorny set of variations on the theme of really tough love.
Origin
French, literally 'shared madness'.