fo·lie à deux 
(fô-lē′ ä dœ, fŏl′ē)
(fô-lē′ ä dœ, fŏl′ē)n.
A condition in which two individuals who share a close relationship experience the same delusions or hallucinations as the result of a mental disorder such as schizophrenia affecting one or both of them. Also called shared psychotic disorder.
[French : folie, madness + à, between + deux, two.]