# Folie à Deux · The Cult Dossier · The Atlas · The Congregation of Tomorrow

Source: https://congregationoftomorrow.org/atlas/library/cults/171-folie-a-deux/ · The Congregation of Tomorrow · the Atlas · language: en
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The Cult Dossier · No. 171 · Shared Psychosis / Mandated Killing
Folie à Deux
Shared psychotic disorder; induced delusional disorder; madness shared by two
1877 – present · France originally; the diagnosis is used worldwide
XVII. SHARED PSYCHOSIS AND THE MANDATE TO KILL
Not religious in itself, though the shared delusion frequently is. Where two isolated people share a religious conviction nobody else can check, this is the clinical description of what is happening.
### Who led it
### What it worshipped and taught
### Who was in it
### How it ended, or where it stands
### The dead
### Of note
### Its timeline
- 1860 JULES BAILLARGER reports the phenomenon. The name comes seventeen years later.
- SEPTEMBER 1877 LASÈGUE AND JULES FALRET publish LA FOLIE À DEUX OU FOLIE COMMUNIQUÉE in the ARCHIVES GÉNÉRALES DE MÉDECINE.
- 20th century The concept is extended to folie à trois, à quatre and à famille — whole households sharing one person's delusion.
- DSM-IV Formalised as SHARED PSYCHOTIC DISORDER.
- DSM-5 (2013) REMOVED AS A SEPARATE DIAGNOSIS. Cases meeting the criteria are now recorded as delusional disorder, or otherwise under other specified schizophrenia spectrum and other psychotic disorders. ICD lists it as INDUCED DELUSIONAL DISORDER. The phenomenon did not go anywhere; the classification of it changed.
- Present THE FIRST STEP IN TREATMENT IS SEPARATION. Removed from the primary, the secondary tends to improve faster than the primary does. IT IS NOT RELIABLE: current clinical reviews warn that separation by itself can be insufficient or can make the condition worse, and antipsychotic treatment is commonly needed as well.
### Its people
### Charles Lasègue
Ernest-Charles Lasègue
French physician; co-named folie à deux · 1816 – 1883 · active 1877
Before the law. None.
Where things stand. Deceased. HIS PAPER IS STILL THE DESCRIPTION EVERYONE USES, a hundred and fifty years on, even though the diagnosis itself was removed from the DSM in 2013. The three conditions he and Falret set out — a dominant primary, a dependent secondary and social isolation — have not needed amending.
- 1816 Born in Paris.
- 1873 Publishes on what is now called anorexia nervosa, independently of Gull in London.
- SEPTEMBER 1877 With JULES FALRET, publishes LA FOLIE À DEUX OU FOLIE COMMUNIQUÉE in the ARCHIVES GÉNÉRALES DE MÉDECINE.
- 1883 Dies.
Checked 2026-09-06
### Jules Falret
Jules Philippe Joseph Falret
French psychiatrist; co-named folie à deux · 1824 – 1902 · active 1877
Before the law. None.
Where things stand. Deceased. THIS FILE INCLUDES HIM SEPARATELY FOR ONE REASON: to make the father-and-son confusion hard to repeat. If a source says Jean-Pierre Falret co-wrote the 1877 paper, that source has not checked, and whatever else it says should be read in that light.
- 1824 Born, into a family already central to French psychiatry.
- 1850s–1870s Works at the Salpêtrière; publishes on delusional states.
- SEPTEMBER 1877 Co-publishes LA FOLIE À DEUX OU FOLIE COMMUNIQUÉE.
- 1902 Dies.
Checked 2026-09-06
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