The Psychosis of Association—folie a Deux

Induced Delusional Disorder

“…These features are related to the three diagnostic criteria for folie à deux proposed by Dewhurst and Todd [16], and also reflect several characteristics now included among the diagnostic criteria for induced delusional disorder and shared paranoid disorder in ICD-10 and DSM-IV (table 2). Thus, the symptomatology is quite well defined, in spite of the fact that there is considerable variation in the individual characteristics of those affected and the broad range of terms used to describe the disorder (table 1).…”

“…Three concise criteria for the diagnosis of folie à deux were proposed by Dewhurst and Todd [16]: (1) the persons involved should be closely associated, (2) the content of the delusions should be identical or very similar, and (3) the persons involved should accept, share and support each others delusions. These criteria have been widely accepted and form the basis for most subsequent definitions of folie à deux, including the definitions rendered in the two most widely used classification schemes: ICD-10 [72] and DSM-IV [2].…”

Lasègue-Falret Syndrome – Folie Simultanée

“…[5] He also went on to explain that the diagnosis need not be restricted to nonconsanguineous patients; it should also be made when family members are involved. [5] Dewhurst and Todd (1956) had put forth three concise criteria which were widely accepted for the diagnosis of folie à deux as follows: [6] 1. There must be marked similarity of the delusional content.…”

Folie a Deux

“…Most of these were concerned with the method by which delusions were transferred from one person to another. Dewhurst (2) considered that subclinical forms were more prevalent, and that a normal variant could be found in isolated groups under faltering leadership. Using his definition this illness must meet the following criteria:…”