Folie à deux and dementia

A Contagious Disorder: Folie à Deux and Dementia

BACKGROUND

Folie à deux is a clinical condition that was first described in 19th century. It is a psychotic disorder in which two closely associated individuals share a similar delusional system.

OBJECTIVES

The aim of this article is to review the nosological significance of folie à deux and to explore the disorder among patients with dementia.

METHODS

Medline and Google Scholar searches were conducted for relevant articles, chapters, and books published before 2017. Search terms used included dementia, folie à deux, induced delusional disorder, neurocognitive disorders, shared psychotic disorder. Publications found through this indexed search were reviewed for further relevant references.

RESULTS AND CONCLUSION

Cases of Folie à deux involving patients with dementia are reported quite infrequently. Most of the studies on the topic consist in case reports. Clinicians are obliged to treat the disorder. They should be alert to the potential high risk inherent this psychotic syndrome.

Induced psychotic disorder: clinical aspects, theoretical considerations, and some guidelines for treatment

We describe our experience with a case of folie à famille with role reversal, including the long-term course. In addition, the case reports published since 1974 were reviewed and an overview is given of the psychoanalytic and system theory concepts on the pathogenesis of induced psychotic disorder. The inductor often appears to be suffering from schizophrenia. No further indications could be found in the literature for a hereditary predisposition in the recipient. It is sometimes difficult to distinguish between the inductor and the recipient, owing to the circular character of induced psychotic disorder and the role reversal that sometimes occurs. The DSM-III-R criteria for induced psychotic disorder were found to be lacking in practice because of their disregard for the circular causality and the strict exclusion criteria. In the short term, physical separation of the inductor and recipient leads to better treatment results than nonseparation, particularly in the case of recipient children. Long-term results are seldom mentioned. On the basis of theoretical considerations, interventions that aim at separation in psychological terms are necessary to achieve favorable long-term treatment results.