Capgras Syndrome: A Brief Introduction

OVERVIEW

Imagine for a brief moment that you come home to your relative or loved one, only for them to claim upon entry that you are not the original you. In fact, they claim that you are an imposter and refuse to listen to your insistence that you’re the person they’ve always known. However, the emotional attachment they would usually feel looking at you has gone. This belief then begins to extend to others in their life, until your loved one is sure they’re surrounded by imposters. 

Conversely, imagine that your loved one comes home, yet you are sure they’re an imposter. They look, act, and sound just like them, but there is no doubt in your mind that they are not the one you know and love so dearly. The familiarity you usually feel looking at and interacting with them has gone, and that absence is so overwhelming that you cannot understand how or why there’s a chance they’re the person you remember. That is a first, and very straightforward, glimpse at Capgras syndrome.

Capgras syndrome (CS), named after the French psychiatrist Joseph Capgras, is, to put it rather simply, a delusion in which a person believes a close loved one, a pet, a belonging, or someone otherwise significant in their life has been replaced by an identical imposter. This delusion can begin with the person they care most about, then progressively extend to others in their life.[1] It is the most widely known and most prevalent delusional misidentification disorder, though has not been listed in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) due to its rarity.[2] Therapy and medication are typically recommended treatments for CS.

HISTORY

One hundred and one years ago, the French psychiatrist Joseph Capgras was the first to officially establish and define Capgras syndrome in a 1923 medical paper in which he describes a patient who believed her husband, children, and even herself were all replaced by identical imposters. Joseph Capgras and Jean Reboul-Lachaux, who co-authored the paper, dubbed this phenomenon "l'illusion des sosies,” which directly translates to the illusion of the doubles or the illusion of look-alikes.[3] 

In this paper, they go in depth about their encounter with the previously mentioned woman, fifty-three year old “Madame M,” who explained that she believed she was surrounded by duplicates of those she knew, starting with herself. She told the two after her hospitalization that, according to her, she was born into aristocracy, but was replaced at birth and that her hospitalization was a ploy to hinder her attempts at doing good with a vast inheritance her great-grandmother has left her. She proceeded to explain the replacement of her children, husband, and even go into depth about duplicates also existing in the hospital ward she had recently arrived in.[4] Though none of her delusional misidentification was true, we can see evidence of distinct delusions co-occurring alongside her case of CS, something not at all uncommon for those with delusional misidentification syndromes. 

CS was viewed at the time as a disorder similar to schizophrenia and hysteria, in turn making it incorrectly viewed as a phenomenon solely linked to women.[2] In fact, in many older cases that we now recognize as CS, the syndrome itself was seen as a symptom of a different psychiatric disorder, rather than it being its own condition that requires an individualized approach. As time slowly went on, however, more breakthroughs in the understanding of CS came to light, as was the case in the 1980s when it was discovered that the development of CS does not purely stem from a psychiatric condition, and can instead be, and is primarily, caused by neurological dysfunction.[5][6]

DEFINITION

Sometimes referred to as imposter syndrome (despite imposter syndrome now being generally accepted as having its own, separate definition), Capgras syndrome is described as the recurrent and momentary false belief that a person, pet, or belonging has been replaced by an identical duplicate.[7] Unlike previous misconceptions, it is now known that those with CS can in fact misidentify inanimate objects and pets, instead of the delusion being solely focused on people significant to their lives. As a matter of fact, people with CS can harbor differing or additional delusions, especially if they also struggle with co-occurring mental health conditions, such as schizophrenia, schizoaffective disorder, or obsessive-compulsive disorder (OCD).[8][9] To put it more simply, the delusion that arises from CS is the belief that something familiar to the individual has been replaced by or transformed into something unfamiliar.[10]

Indeed, it is not entirely uncommon to see individuals with CS also be diagnosed with or report other psychiatric conditions. However, it is also just as true that CS can arise from a multitude of origins including but not limited to prior mental health conditions, neurodegenerative disease, head trauma, drug use, or, interestingly enough, even illnesses such as a urinary-tract infection.[9][11] Further, CS is primarily a visual misidentification delusion. This is to say that if an individual with CS hears the person they believe has been replaced without seeing them, they’ll be able to know that it’s actually them.[12]

Contrary to popular belief, it’s also possible for people with CS to be aware of the irrationality of their delusions, especially if they have OCD. A case report from 2013 by Maria Luca et al. found surprising overlap between CS and OCD, specifically “cases in which the delusional ideation is associated with deep feelings of disgust and presents with a certain pervasiveness,” according to the study.[9] Nonetheless, this is a rare occurrence. 

CAUSES & TREATMENT

Under one percent of the general population struggles with Capgras syndrome. Despite this, CS can arise from a variety of causes. It’s been found increasingly common for a majority to suffer from neurodegenerative diseases and neurological conditions, such as Parkinson’s, dementia, Alheizmer’s disease, epilepsy, and so on.[1] Neurodegenerative diseases can alter a person’s sense of memory and reality, putting them at a higher risk of developing CS than most. Lewy body dementia was found to be particularly common among those with CS.[7]

As previously mentioned, head trauma is also a pinpointed origin of CS. To elaborate, the brain has specialized regions that are responsible for a person’s memory in regard to facial distinguishing and recognition. One of these regions is the temporal cortex, which allows for an individual to process and recognize others by their facial features.[13] Damage to this area, the bifrontal, and right limbic regions of the brain have been known to produce CS or CS-like delusions.[14] According to Rosalía Hillers Rodríguez et al., “memory, feeling of familiarity, monitoring of self and reality would be altered” as a result.[14] This prevents the brain from assigning emotional and sentimental significance to the face of an individual the person knows and cares for, further prohibiting the person’s ability to recognize familiar faces. This lack of familiarity is one of the primary driving forces behind CS delusions. Impairment to the fusiform gyrus, amygdala (regions of the brain that also play a role in facial recognition and emotion), and their connection to each other can also result in CS or CS-like symptoms.[12] 

A key thing to note is that impairment to regions of the brain that are particularly responsible for assigning emotional significance and familiarity to a person’s face is important in the development of CS. If only the ability to assign memory to a person’s face is damaged (i.e. the right fusiform gyrus), prosopagnosia, otherwise known as face blindness, can result without CS delusions.[15] In spite of this, it has been documented that prosopagnosia can co-occur with CS.[2][16] Similarly, CS can also co-occur with other delusional misidentification syndromes such as reduplicative paramnesia, a delusion in which an individual believes a location has been duplicated or relocated, because the same regions of the brain are affected.[2]

CS can also occur due to prior mental health conditions. People who struggle with schizophrenia, schizoaffective disorder, bipolar disorder, obsessive-compulsive disorder, different types of psychosis, and other similar conditions experience a higher risk of developing CS than those who do not. For example, it was reported in a 2019 study that reviewed 258 with CS, around 32% had also been diagnosed with schizophrenia.[17] Other health problems such as a urinary-tract infection have also been reported to cause transient CS and CS symptoms.[11] Further research is needed on the overlap between non-neurodegenerative illness and CS, however. Additionally, CS and CS-like delusions have also been associated with substance abuse.[7][18][19]

Treatment options for CS vary widely and are dependent on individual cases and underlying causes. The most commonly recommended include therapy and medication (often prescribed together), such as cognitive-behavioral therapy, habilitation therapy, antipsychotic medications, dementia medications, and so on.[20] Hospitalization is a mandatory course of action if the individual is or is at risk of harming themselves or others. Surgery or neurorehabilitation are also available treatment options if the underlying cause was damage to the brain.[1] Therapy or counseling may also be offered to loved ones of those struggling with CS in order to both help them understand that the individual is not acting out of malice and to further help loved ones process their emotions regarding the situation. Furthermore, loved ones, particularly those who are believed to have been replaced, can play a crucial role in an individual’s rehabilitation. Auditory interactions without face-to-face communication are highly encouraged[2]. This allows the individual to emotionally connect with their loved ones in a way they previously could not as a result of their CS.

CONCLUSION

Despite being the most prevalent delusional misidentification syndrome, there is still so much unknown about Capgras syndrome. However, researchers and doctors have been able to help those struggling to the best of their ability. Improvement in this area of healthcare is always necessary and further research, no matter how difficult, will prove beneficial in treating and providing support to those with CS and their loved ones. If you or a loved one is struggling, please know that help is always available. 

REFERENCES

1. Capgras Syndrome. (2023). Psychology Today. https://www.psychologytoday.com/us/basics/capgras-syndrome 

2. Shah, K. P., Jain, S. B., & Wadhwa, R. (2023, May 29). Capgras Syndrome. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK570557/# 

3. Résultats de recherche — Medica — BIU Santé, Paris. (2014). U-Paris.fr. https://numerabilis.u-paris.fr/medica/bibliotheque-numerique/resultats/index.php?do=page&cote=epo1250&p=1 

4. Carson, A. (2023). Capgras syndrome. Brain, 146(10), 3955–3957. https://doi.org/10.1093/brain/awad294 

5. Merrin, E. L. (1976). The Capgras Phenomenon. Archives of General Psychiatry, 33(8), 965–965. https://doi.org/10.1001/archpsyc.1976.01770080083008 

6. Wilcox, J. A. (1984). A Case of Capgras’ Phenomenon. Australian & New Zealand Journal of Psychiatry, 18(4), 391–392. https://doi.org/10.3109/00048678409158803 

7. Josephs, K. A. (2007). Capgras Syndrome and Its Relationship to Neurodegenerative Disease. Archives of Neurology, 64(12), 1762–1762.

https://doi.org/10.1001/archneur.64.12.1762 

8. Capgras Syndrome. (2023). Psychology Today. https://www.psychologytoday.com/us/basics/capgras-syndrome 

9. Luca, M., Bordone, A., Luca, A., Patti, A., Sortino, G., & Calandra, C. (2013, August 13). Clinical features and imaging findings in a case of Capgras syndrome [Review of Clinical features and imaging findings in a case of Capgras syndrome]. Taylor & Francis Online. https://www.tandfonline.com/doi/full/10.2147/NDT.S47293#d1e146 

10. What is Capgras delusion? (2022). Cognitive Neuropsychiatry. https://doi.org/10.1080//13546805.2021.2011185 

11. Bersani, F. S., None Salviati, None Macrì, None Fojanesi, Minichino, N., Gallo, N., Michele, N. D., Delle Delle Chiaie, & Biondi, N. (2013). Capgras-like syndrome in a patient with an acute urinary tract infection. Neuropsychiatric Disease and Treatment, 139–139. https://doi.org/10.2147/ndt.s39077 

12. Capgras» the nerve blog | Boston University. (2024). Bu.edu. https://sites.bu.edu/ombs/tag/capgras/#:~:text=The%20Capgras%20Delusion%20is%20caused,person%20in%20front%20of%20them. 

13. NIH researchers discover a new face-detecting brain circuit. (2024, July). National Institutes of Health (NIH). https://www.nih.gov/news-events/news-releases/nih-researchers-discover-new-face-detecting-brain-circuit#:~:text=In%20adult%20primates%2C%20the%20brain,individuals%20by%20their%20facial%20features. 

14. Rosalía Hillers Rodríguez, Agustín Madoz-Gúrpide, & Ustárroz, J. T. (2011). Propuesta de una batería neuropsicológica para la exploración del síndrome de Capgras. Revista Española de Geriatría Y Gerontología, 46(5), 275–280. https://doi.org/10.1016/j.regg.2011.06.001 

15. Barton, J. J. S., Press, D. Z., Keenan, J. P., & O’Connor, M. (2002). Lesions of the fusiform face area impair perception of facial configuration in prosopagnosia. Neurology, 58(1), 71–78. https://doi.org/10.1212/wnl.58.1.71 

16. Shraberg D;Weitzel WD. (2024). Prosopagnosia and the Capgras syndrome. The Journal of Clinical Psychiatry, 40(7). https://pubmed.ncbi.nlm.nih.gov/457623/ 

17. Pandis, C., Agrawal, N., & Poole, N. (2019). Capgras’ Delusion: A Systematic Review of 255 Published Cases. Psychopathology, 52(3), 161–173. https://doi.org/10.1159/000500474 

18. Mercurio, E. N. (2011). Capgras Syndrome associated with the use of psychoactive substances. Revista de Psiquiatría Y Salud Mental (English Edition), 4(2), 96–100. https://doi.org/10.1016/s2173-5050(11)70015-2 

19. Milena, D., Ayala, L. S., Saavedra, S., García, S., & Herrera, F. (2022). Capgras Syndrome Due to Cannabinoids Use: A Case Report With Radiological Findings. Cureus. https://doi.org/10.7759/cureus.21412 

20. Capgras Syndrome: What It Is, Causes, Symptoms & Treatment. (2024, October 16). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/capgras-syndrome#symptoms-and-causes