<unk>  (literally, "a madness shared by two") is a rare psychiatric syndrome in which a symptom of psychosis (particularly a paranoid or delusional belief) is transmitted from one individual to another. The same syndrome shared by more than two people may be called<unk> <unk>  trois,<unk> <unk>  quatre,<unk> <unk>  famille or even<unk> <unk>  plusieurs (madness of many). Recent psychiatric classifications refer to the syndrome as shared psychotic disorder (DSM-IV) (297.3) and induced delusional disorder<unk>  (F.24) in the ICD-10, although the research literature largely uses the original name.
Folie à deux
Psychopathy
Munchausen syndrome by proxy
Apophenia
Battered person syndrome
Depersonalization disorder
Disorganized schizophrenia
Dissociative disorders