Folie à Deux: Shared Psychotic Disorder

Folie à Deux (pronounced fo-lee uh doo) is a rare mental health disorder that can be difficult to understand but can be treated successfully when professional help is sought.  This article will discuss what it is, the treatment and provide resources for persons dealing with a loved one with this disorder.

Face Silhouette Brain Exchange Exchange OfFolie à Deux: What Does It Mean?   

Folie à Deux literally mean a madness or insanity shared by two people.  In essence it means two people that share a delusion and support each other in their delusion.  A delusion is a false belief that a person strongly believes and does not go away just by telling a person that its not real.  It requires treatment and often times medication.    

Stats: How Many Suffer from this Disorder?

Folie à deux is a rare disorder and there is not much information on it.  Because of that, it is not known how many people suffer from this as there are only case studies that are shared.  

What Causes Folie à Deux?

It is unknown what causes this disorder, but what is known is that one person suffers from a psychotic disorder and the other person comes to believe the delusion.  Almost 100% of the cases involve persons in close emotional relationships, such as husband and wife, siblings or parent and child.  This disorder has rarely been seen in persons who do not have a close relationship.  The person who comes to believe the delusion will most likely have a predisposition to psychosis, although it may never manifests completely.  Research shows there is no way to prevent this disorder and almost impossible to predict whether a person will ever develop it.  

Signs and Symptoms of Folie à Deux

While it is unknown why this disorder happens, there are some signs to look out for.  Most people with Folie à Deux are passive in nature, may be socially isolated, may have a histrionic personality traits, is very dependent on the person who has a psychotic or delusional disorder, and are more often women.

What are the Common Behaviors/Characteristics?

Common characteristics of someone with Folie à Deux is:

  1. They have adopted the delusion from someone whom they are in a close emotional relationship with and support the other persons belief.
  2. They do not have a psychotic or delusional disorder and have been relatively healthy but may have lower self esteem or may even have a predisposition to a psychotic disorder.  
  3. Evidence suggests that the passive person did not previously have this belief and was brought upon by being in a relationship with, of some kind, the person who is delusional.
  4. The person who takes on the delusion is more often female.
  5. It has been mostly shown in persons who are in a relationship with someone older than themselves.

Testing: What are the Diagnostic Criteria Per the DSM 5?

The DSM 5 states all of these must be present to have a diagnosis of Folie à deux:

  • Two people share the same delusion or delusional system and support one another in this belief.
  • They have an unusually close relationship.
  • Temporal or contextual evidence exists that indicates the delusion was induced in the passive member by contact with the active partner.

Folie à Deux and Other Conditions

There are other conditions in which two people share a delusion but are even more rare:

  1. Folie à trios- the delusional is shared by 3 people
  2. Folie à quatro- the delusion is shared by 4 people
  3. Folie à famille- the delusion is shared by an entire family
  4. Folie à plusiers- the delusion is shared by many, as in the case of cults.

Folie à Deux vs Delusional Disorder

Folie à deux is when two people share the same delusion and only one person is diagnosed with a psychotic disorder while the other person who took on the delusion is relatively healthy.  A delusional disorder, by contrast, is when a psychotic disorder is not shared with another person but rather is independent in nature.  

Secondary vs Primary Delusional Disorder

Primary Delusional Disorders are delusions that may happen out of the blue and can be understood by others.  It is a delusion with no basis or explanation.

Secondary delusions are ones that, although they are not correct, may come from an experience or situation that happened that has led the person to now believe the delusion.  An example would be when a person is depressed and thinks that they are depressed because they are being punished for something.

Related Conditions

Schizophrenia is a psychotic disorder where an individual hears voices and will often have delusions or hallucinations, however hearing voices are the hallmark of this disorder.  

Psychosis refers to a persons thoughts and emotions being so impaired that they are unable to function on a daily basis.  This differs from Folie à Deux where a person is usually functioning in all aspects of their life but has adopted the delusion.  

Example Case of Folie à Deux

In 2014, two 12 year old girls (Morgan Geyser and Anissa Weier) killed a man they thought was Slenderman (a fictional character whom they thought was real), because they felt that if they didn’t then he would kill them and their families.  Later it was determined by a psychologist who assessed both girls, that Morgan Geyser had early onset schizophrenia, and her friend Anissa Weier came to adopt the same delusion after the two friends became close.  According to Anissa’s parents, she was shy, didn’t have many friends, and eager to make friends.  After the two girls were arrested and separated, slowly Anissa began to realize that her delusion was false after receiving therapy and support from her family. 

How to Deal/Coping With Folie à Deux

Coping with Folie à Deux can be stressful and confusing.  Seeking support from others and seeking professional help for yourself if you have a family member with this can be beneficial.  Its important that family and friends understand this disorder as much as possible and support their loved one who may have this disorder.  Remember this is not a disorder by choice and the person affected actually believes this delusion.  They are not doing this to seek attention and it is not a sign of weakness, rather it is a serious disorder that should be carefully handled with the help of a licensed mental health professional.  Separating the two people is the best way to treat this disorder but can be difficult and should not be forced without the help of others.  

Look out for These Complications/Risk Factors

It can sometimes be difficult for someone to recognize this Folie à Deux because the affected person may appear to be relatively healthy and seem to act “normal”.  When interviewing a person with this disorder, nothing may seem out of the ordinary until the delusion is discussed.  The affected person may become anxious or angry when challenged with this delusion and should therefore be done with the support of others.

Folie à Deux Treatment

The most powerful treatment for Folie à Deux is separating the two individuals.  It has been proven that when the person who has been influenced is separated from the primary person and given therapy, the delusion tends to diminish.  At times it may be necessary to prescribe medication for  to the affected person when separating doesn’t work.  The person affected would benefit from therapy to understand why they came to believe the delusion and to work on other things such as dependency issues, self esteem and confidence.  Family therapy can also be helpful to assist the entire family in understanding why this happened and how to better support the person affected.  

Possible Medications for Folie à Deux      Medicine Medical Pharmaceuticals Drug Logo                

Medication is often used to assist the person who has the psychotic disorder with their symptoms.  Although it is not usually used on the secondary person, it may be worth considering if other techniques don’t work.  Medications such as antipsychotics work well.  These medications include Haldol and Thorazine which are considered first generation anti psychotic medications.  These medications should be given by a psychiatrist and the patient needs to monitored closely.

Home Remedies to help Folie à Deux

There are no known home remedies for persons suffering from Folie à Deux.  

Living with Folie à Deux

Living with Folie à Deux can be very stressful for friends and family members.  Its important to remember to be patient but also persistent with treatment.  Trying to separate the two people involved is most beneficial, however, that can be a difficult task due to the close emotional tie the two people share.  There is often dependency with the primary person as well.  

Insurance Coverage for Folie à Deux

Because Folie à Deux is a mental health disorder classified in the DSM 5, it is treated by insurance for persons that have behavioral health coverage.  To learn more about your coverage, contact your insurance company.

How to Find a Therapist

Finding a licensed mental health therapist can be done by searching Psychology Today online or by going to There you can find therapists, psychiatrists and support groups that can assist with the treatment of this disorder.  

What Should I be Looking for in a LMHP?

When searching for a LMHP, be sure to find someone who specializes or has extensive experience working with psychotic disorders or delusional disorders.  You also want to make sure that the LMHP thoroughly understands Folie à Deux and knows how to treat it.  It is important that the person listen to you and asks questions to get an understanding of your situation.  Most people continue working with an LMHP that they feel comfortable with and whom they feel are listening and attentive. 

Questions to Ask a Potential Therapist

When contacting an LMHP. you want to make sure the person is a potential fit before scheduling an appt or at the initial visit.  Some questions to ask a potential therapist are:

  1. Tell me what you know about Folie à Deux?
  2. Have you ever treated someone with this disorder, and if so, how many?
  3. What is your technique that you use to treat this disorder?
  4. How involved do I need to be in the process?

Folie à Deux Resources and Support Helpline

Although there is limited information on Folie à Deux, the research is growing and this disorder has been accepted by more treating professionals. provides resources online but also provides a phone number of specialists that can be reached 24 hours a day/365 days per week.  These specialists are there to help you find the treatment you are looking for a resources for successful treatment.  Their phone number is 800-598-5053.

Folie à Deux is a rare mental health disorder that is recognized among mental health professionals as a delusion shared between two people, with one being the primary (the person with a psychotic disorder that has the delusion) and the other person being secondary (the person who comes to believe this delusion).  The secondary person is the one who is diagnosed with Folie à Deux as they are the one that is relatively healthy but have taken on the delusion.  This disorder occurs when two people have an extremely emotional closeness that is sometimes unusual in nature.  There is usually a dependency by the secondary person on the primary person and some characteristics that have been seen in persons with Folie à Deux are shyness, isolation, and low self esteem.  While much research doesn’t exist, there have been cases studied and it has been determined that this disorder can be treated by being separated from the primary person and at times may have to take medication for a short period of time.  This disorder can be hard to understand and difficult to deal with but there are licensed mental health professionals that are equipped to treat this disorder in the individual affected as well as the loved ones that are involved.   Persons with this disorder can seemingly appear normal and typically function at a high level in their day to day lives.  The only thing that is generally out of place is the delusion that the two people share.  Help is available and research continues to grow.  Seek support of persons around you and remember that patience and understanding are important when dealing with a person with Folie à Deux.  

author avatar
Angel Rivera
I am a Bilingual (Spanish) Psychiatrist with a mixture of strong clinical skills including Emergency Psychiatry, Consultation Liaison, Forensic Psychiatry, Telepsychiatry and Geriatric Psychiatry training in treatment of the elderly. I have training in EMR records thus very comfortable in working with computers. I served the difficult to treat patients in challenging environments in outpatient and inpatient settings
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