A La Folie 2022
Brunilda Chestnut
Folie deux (French for 'madness of two'), also known as shared psychosis[2] or shared delusional disorder (SDD), is a psychiatric syndrome in which symptoms of a delusional belief[3] are "transmitted" from one individual to another.[4]
This disorder is not in the current, fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which considers the criteria to be insufficient or inadequate. DSM-5 does not consider Shared Psychotic Disorder (folie deux) as a separate entity; rather, the physician should classify it as "Delusional Disorder" or in the "Other Specified Schizophrenia Spectrum and Other Psychotic Disorder" category.
Folie deux and its more populous derivatives are psychiatric curiosities. The current Diagnostic and Statistical Manual of Mental Disorders states that a person cannot be diagnosed as being delusional if the belief in question is one "ordinarily accepted by other members of the person's culture or subculture". It is not clear at what point a belief considered to be delusional escapes from the folie ... diagnostic category and becomes legitimate because of the number of people holding it. When a large number of people may come to believe obviously false and potentially distressing things based purely on hearsay, these beliefs are not considered to be clinical delusions by the psychiatric profession, and are instead labelled as mass hysteria.
As with most psychological disorders, the extent and type of delusion varies, but the non-dominant person's delusional symptoms usually resemble those of the inducer.[9] Prior to therapeutic interventions, the inducer typically does not realize that they are causing harm, but instead believe they are helping the second person to become aware of vital or otherwise notable information.
As with many psychiatric disorders, shared delusional disorder can negatively impact the psychological and social aspects of a person's wellbeing. Unresolved stress resulting from a delusional disorder will eventually contribute to or increase the risk of other negative health outcomes, such as cardiovascular disease, diabetes, obesity, immunological problems, and others.[13] These health risks increase with the severity of the disease, especially if an affected person does not receive or comply with adequate treatment.
People with a delusional disorder have a significantly high risk of developing psychiatric comorbidities such as depression and anxiety. This may be attributable to a genetic pattern shared by 55% of SDD patients.[14]
Shared delusional disorder can have a profoundly negative impact on a person's quality of life.[15] Persons diagnosed with a mental health disorder commonly experience social isolation, which is detrimental to psychological health. This is especially problematic with SDD, as social isolation contributes to the onset of the disorder; in particular, relapse is likely if returning to an isolated living situation, in which shared delusions can be reinstated.
People who are socially isolated together tend to become dependent on those they are with, leading to an inducer becoming able to influence those around them. Additionally, people developing shared delusional disorder do not have others reminding them that their delusions are either impossible or unlikely. As a result, treatment for shared delusional disorder includes those affected be removed from the inducer.[17]
Stress is also a factor, as it is a common factor in mental illness developing or worsening. The majority of people that develop shared delusional disorder are genetically predisposed to mental illness, but this predisposition alone is not enough to develop SDD. In other words, stress is a risk factor of this disorder. When stressed, an individual's adrenal gland releases the stress hormone cortisol into the body, increasing the brain's level of dopamine; this change can be linked to the development of a mental illness, such as a shared delusional disorder.[14]
While there is no exact cause of shared psychosis, there are several factors that are contributors depending on different cultures and communities and taking into consideration the individual's circumstances, including their environmental changes and relationships.
Shared delusional disorder is often difficult to diagnose. Usually, the person with the condition does not seek out treatment, as they do not realize that their delusion is abnormal, as it comes from someone in a dominant position whom they trust. Furthermore, since their delusion comes on gradually and grows in strength over time, their doubt is slowly weakened during this time. Shared delusional disorder is diagnosed using the DSM-5, and according to this, the patient must meet three criteria:[9]
Shared delusional disorder is most commonly found in women with slightly above-average IQs, who are isolated from their family, and who are in relationships with a dominant person who has delusions. The majority of secondary cases (people who develop the shared delusion) also meet the criteria for dependent personality disorder, which is characterized by a pervasive fear that leads them to need constant reassurance, support, and guidance.[20] Additionally, 55% of secondary cases had a relative with a psychological disorder that included delusions and, as a result, the secondary cases are usually susceptible to mental illness.
After diagnosis, the next step is to determine the proper course of treatment. The first step is to separate the formerly healthy person from the inducer, and see if the delusion goes away or lessens over time.[17] If this is not enough to stop the delusions, there are two possible courses of action: medication or therapy. Therapy can be provided as both personal therapy or family therapy.
With treatment, the delusions, and therefore the disease, will eventually lessen so much so, that it will practically disappear in most cases. However, if left untreated, it can become chronic and lead to anxiety, depression, aggressive behavior, and further social isolation. Unfortunately, there are not many statistics about the prognosis of shared delusional disorder, as it is a rare disease, and it is expected that the majority of cases go unreported; however, with treatment, the prognosis is very good.
If the separation alone is not working, antipsychotics are often prescribed for a short time to prevent the delusions. Antipsychotics are medications that reduce or relieve symptoms of psychosis such as delusions or hallucinations (seeing or hearing something that is not there). Other uses of antipsychotics include stabilizing moods for people with mood swings and mood disorders (i.e. in bipolar patients), reducing anxiety in anxiety disorders, and lessening tics in people with Tourettes. Antipsychotics do not cure psychosis, but they do help reduce symptoms; when paired with therapy, the person with the condition has the best chance of recovering. While antipsychotics are powerful, and often effective, they do have side effects, such as inducing involuntary movements. They should only be taken if absolutely required, and under the supervision of a psychiatrist.[21]
Personal therapy is one-on-one counseling that focuses on building a relationship between the counselor and the patient, and aims to create a positive environment where the patient feels that they can speak freely and truthfully. This is advantageous, as the counselor can usually get more information out of the patient to get a better idea of how to help them. Additionally, if the patient trusts what the counselor says, disproving the delusion will be easier.[22]
Family therapy is a technique in which the entire family comes into therapy together to work on their relationships, and to find ways to eliminate the delusion within the family dynamic. For example, if someone's sister is the inducer, the family will have to get involved to ensure the two stay apart, and to sort out how the family dynamic will work around that. The more support a patient has, the more likely they are to recover, especially since SDD usually occurs due to social isolation.[23]
As a species, we are more herdlike than we are hermetic. Both tendencies exist in our society, but we tend to be happier and healthier when we herd as a group together than when we isolate ourselves. In fact, it has been established that even individuals without a history of mental illness are more likely to develop symptoms if they experience too much isolation, loneliness, or withdrawal from social connections.
I saw one couple who remained isolated from outside social influence for more than 15 years. Individually, they looked perfectly normal, but together both were as mad as Hatters. Another couple remained isolated from outside social influence for more than nine years. No one knew of their existence as a couple. As individuals, they were both hugely successful, but as partners in a couple they were a huge mess. In each folie deux case, the partners became sicker and crazier over time.
When considering the etiologic factors of the disorder, the most important seems to be the familial and interpersonal dynamics. The inducer (primary) usually plays a dominant role with an impressionable secondary, who might have limited intellect or a personality disorder.5 Other factors include socioeconomic challenges, geographical isolation, and language difficulties. In 1995, Silveira and Seeman6 found equal age and sex prevalence; couples, siblings, and parent/child pairs represented 90% of cases; two-thirds were socially isolated; and depression, dementia, and mental retardation were the common comorbidities. The theories surrounding this disorder include psychodynamic theory (isolated secondary fears losing a significant loved one or repressed oedipal fantasies realized in the backdrop of psychosis), learning theory (learning through observation), and social isolation theory.7
Due to the rarity of this disorder presenting in a clinical setting, the exact presentation, clinical course, and prognosis are not fully understood. The case presented here of a delusional secondary patient attempts to add to the scarce epidemiologic literature.
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