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Two identical twin sisters had folie deux (or "shared psychotic disorder") which resulted in both bizarrely attempting suicide. One sister was hospitalized, and the other was jailed. The next day, a psychiatrist made a terrible blunder by releasing the sister from jail. She then murdered a man who tried to help her.


Induced Delusional Disorder F24 - ICD10 Description, World Health Organization
A delusional disorder shared by two or more people with close emotional links. Only one of the people suffers from a genuine psychotic disorder; the delusions are induced in the other(s) and usually disappear when the people are separated.
Other Psychotic Disorder (Shared) - Diagnostic Criteria, American Psychiatric Association

An individual diagnosed with other psychotic disorder (shared) needs to meet all of the following criteria:

  • Has symptoms of a psychotic disorder that cause clinically signficant distress or impairment in social, occupational, or other important areas of functioning predominate but do not meet the full criteria for any of the disorders in the schizophrenia spectrum and other psychotic disorders diagnostic class.

  • Shared delusional symptoms induced by a delusional, dominant partner: In the context of a relationship, the delusional material from the dominant partner provides content for delusional belief by the individual who may not otherwise entirely meet criteria for delusional disorder.

This is a delusional disorder in which one "genuinely" delusional person induces the same delusion in another person. The two individuals are in a close relationship (e.g., mother-child, or sibling-sibling). The "induced" delusions usually disappear when the delusional pair are separated. The "genuinely" delusional person usually has schizophrenia, delusional disorder or psychotic major depressive disorder. This disorder is not due to schizophrenia, a drug, medication, or other medical disorder.

Effective Therapy

The two delusional individuals must be separated. Usually the individual with "induced" delusions regains sanity once separated from the other partner who is "genuinely" delusional. The "genuinely" delusional individual requires standard antipsychotic treatment for psychosis.

Excellent Very Honest Documentary On Bellevue Psychiatric Hospital



Free Diagnosis Of This Disorder


  • Folie deux: update of an old concept regarding two cases This rare disorder frequently involves mother-daughter associations where the mother has schizophrenia and the daughter adopts her mother's delusions. The separation of the two subjects has to be the basis of any intervention. The inducing subject has to be treated with antipsychotics. Sometimes, the separation is enough to eliminate the delusional ideas from the induced subject.


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