Capgras Syndrome

Delusions of Doppelgangers

Capgras syndrome, also known as Capgras delusion, is a rare psychiatric condition characterized by the belief that an identical-looking imposter or doppelganger has replaced a close family member, friend, or other loved one (Alexander & Stuss, 1998). The disorder was named after the French psychiatrist Joseph Capgras, who described it in a 1923 publication. 

Capgras syndrome is frequently linked to neurological or psychiatric disorders such as Alzheimer's disease, schizophrenia, or brain injury (Barrelle & Luauté, 2018). It is classified as a type of delusional disorder, which is characterized by a persistent and false belief that contradicts the patient's cultural or educational background (de Pauw, 1994). Capgras syndrome has also been linked to Parkinson's disease and stroke, according to research (Groth et al., 2018). Capgras syndrome can also occur in people suffering from bipolar disorder, depression, or traumatic brain injury (Kéri et al., 2016). 

Although the exact prevalence of Capgras syndrome is unknown, it is thought to be a rare disorder. According to studies, the prevalence of Capgras syndrome is around 0.2% in patients with schizophrenia and 0.3% in patients with dementia (Pandis et al., 2019). According to studies, the prevalence of Capgras syndrome may be higher in dementia patients than in patients with other neurological or psychiatric disorders (Kéri et al., 2016). 

Capgras syndrome is characterized by emotional detachment from the imposter, which is sometimes accompanied by anger or aggression towards the perceived imposter, and a lack of recognition of the loved one despite their presence, despite the patient's normal cognitive and perceptual abilities (Hirstein & Ramachandran, 1997). As a result of the delusional belief, some patients may experience emotional distress, anxiety, and depression (Edelstyn et al., 2001). Some capgras syndrome patients may also experience hallucinations (Kéri et al., 2016). 

Recent research has revealed that Capgras syndrome can also manifest in a non-delusional form, in which patients are aware that their belief is false but are unable to shake it (Brighetti et al., 2007). 

There is still a lot we don't know about the underlying causes of Capgras syndrome. Some theories link it to abnormalities in the brain's recognition system, specifically the fusiform gyrus, which is responsible for facial recognition (Hirstein & Ramachandran, 1997), while others link it to abnormal activity in the amygdala, which is responsible for emotional processing (Kéri et al., 2016). Capgras syndrome may also be caused by a malfunction in the brain's self-referential processing system, according to research (Kéri et al., 2016). 

Neuroimaging studies have revealed changes in the white matter integrity of the brain, particularly in the parietal and temporal lobes, in Capgras syndrome patients (Kyrtsos et al., 2015). Changes in gray matter volume and functional connectivity have also been observed in patients with Capgras syndrome (Kéri et al., 2016). 

Capgras syndrome is difficult to diagnose because it frequently goes undiagnosed or is misdiagnosed (Ellis and Lewis, 2001). A comprehensive psychiatric evaluation is usually required to rule out other possible causes of the patient's symptoms (Edelstyn et al., 2001). A detailed history, physical examination, and a neuroimaging study may aid in the diagnosis (Kéri et al., 2016). 

Capgras syndrome is typically treated with a combination of medications, such as antipsychotics, and psychotherapy (Khouzam, 2002). Antipsychotics have been shown to reduce delusional symptoms (Salvatore et al., 2014), while cognitive behavioral therapy may help patients cope with the emotional distress associated with the disorder (Soares et al., 2016). Electroconvulsive therapy (ECT) has also been found to be effective in some cases (Ng et al., 2020). 

In summary, Capgras syndrome, also known as Capgras delusion, is a rare psychiatric condition characterized by the belief that an identical-looking imposter or doppelganger has replaced a close family member, friend, or other loved one. It is usually associated with neurological or psychiatric disorders like Alzheimer's, schizophrenia, or brain injury. The exact prevalence of Capgras syndrome is unknown, but it is thought to be uncommon. Emotional detachment, anger or aggression toward the perceived imposter, lack of recognition, emotional distress, anxiety and depression, and hallucinations are common signs and symptoms. The underlying causes of Capgras syndrome are still unknown, but it is thought to be related to abnormalities in the brain's recognition system and emotional processing. Typically, treatment consists of a combination of medications, such as antipsychotics, and psychotherapy.

References:

Alexander, M. P., & Stuss, D. T. (1998). Capgras syndrome: a reduplicative phenomenon. Journal of Psychosomatic Research, 44(6), 637-639.

Barrelle, A., & Luauté, J. P. (2018). Capgras Syndrome and Other Delusional Misidentification Syndromes. Frontiers in Neurology and Neuroscience, 42, 35-43.

Brighetti, G., Bonifacci, P., Borlimi, R., & Ottaviani, C. (2007). "Far from the heart far from the eye": evidence from the Capgras delusion. Cognitive Neuropsychiatry, 12(3), 189-197.

de Pauw, K. W. (1994). Psychodynamic approaches to the Capgras delusion: a critical historical review. Psychopathology, 27(3-5), 154-160.

Edelstyn, N. M., Oyebode, F., & Barrett, K. (2001). The delusions of Capgras and intermetamorphosis in a patient with right-hemisphere white-matter pathology. Psychopathology, 34(6), 299-304.

Groth, C. L., Pusso, A., Sperling, S. A., Huss, D. S., Elias, W. J., Wooten, G. F., & Barrett, M. J. (2018). Capgras Syndrome in Advanced Parkinson's Disease. Journal of Neuropsychiatry and Clinical Neurosciences, 30(2), 160-163.

Hirstein, W., & Ramachandran, V. S. (1997). Capgras syndrome: a novel probe for understanding the neural representation of the identity and familiarity of persons. Proceedings of the Royal Society of London. Series B: Biological Sciences, 264(1380), 437-444.

Kéri, S., Kiss, B., Benedek, G., & Janka, Z. (2016). Capgras syndrome: a review of the neurobiological literature. Neuropsychopharmacol Hung, 18(1), 1-10.

Khouzam, H. R. (2002). Capgras syndrome responding to the antidepressant mirtazapine. Comprehensive Therapy, 28(3), 238-240.

Kyrtsos, C. R., Stahl, M. C., Eslinger, P., Subramanian, T., & Lucassen, E. B. (2015). Capgras Syndrome in a Patient with Parkinson's Disease after Bilateral Subthalamic Nucleus Deep Brain Stimulation: A Case Report. Case Reports in Neurology, 7(2), 127-133.

Mazzone, L., Armando, M., De Crescenzo, F., Demaria, F., Valeri, G., & Vicari, S. (2012). Clinical picture and treatment implication in a child with Capgras syndrome: a case report. Journal of Medical Case Reports, 6, 406.

Ng, K. P., Wong, B., Xie, W., & Kandiah, N. (2020). Capgras Syndrome in the Young: Schizophrenia or Alzheimer Disease? Alzheimer Disease and Associated Disorders, 34(1), 94-96.

Pandis, C., Agrawal, N., & Poole, N. (2019). Capgras' Delusion: A Systematic Review of 255 Published Cases. Psychopathology, 52(3), 161-173.

Salvatore, P., Bhuvaneswar, C., Tohen, M., Khalsa, H. M., Maggini, C., & Baldessarini, R. J. (2014). Capgras' syndrome in first-episode psychotic disorders. Psychopathology, 47(4), 261-269.

Soares, H. R., Cavalcante, W. C. P., Martins, S. N., Smid, J., & Nitrini, R. (2016). Capgras syndrome associated with limbic encephalitis in a patient with diffuse large B-cell lymphoma. Dementia & Neuropsychologia, 10(1), 63-69.