(psychiatry) A rare syndrome in which a symptom of psychosis (particularly a paranoid or delusional belief) is transmitted from one person to another.

(psychiatry) A form of shared psychotic disorder in which three individuals have the same or similar delusional beliefs, usually by transference.

(psychiatry) Pathological doubting about all affairs of life and indecisiveness in choice situations.

(psychiatry) Delusional beliefs shared by multiple, if not all, members of a family.

delusion of grandeur

plural of folie à deux

plural of folie de grandeur