Folie à deux is a psychiatric entity characterized by the transfer of delusional ideas from one person, the primary patient, to another, the secondary patient. That the syndrome has excited the special interest of psychiatrists is evidenced by the fact that in spite of its relatively infrequent occurrence, over 200 articles describing it have been published, most of these attempting to explain why one person adopts the psychosis of another. In this paper we will describe the psychodynamics underlying the transfer of the delusion in 3 cases. We refer the interested reader to Gralnick1 for more details about definition, classification, and description.
Review of the Literature on Etiology
Theories concerning the transfer of the delusion in folie à deux can be divided into 2 main groups: hereditary-constitutional and environmental-psychological. This review will deal with the latter.For the most part, these theories have been
PULVER SE, BRUNT MY. Deflection of Hostility in Folie à Deux. Arch Gen Psychiatry. 1961;5(3):257-265. doi:10.1001/archpsyc.1961.01710150039007