The Delusion of Doubles: When Familiar Faces Become Strangers Capgras Syndrome and its Clinical Implications

The Delusion of Doubles: When Familiar Faces Become Strangers Capgras Syndrome and its Clinical Implications

Mrs. X. Aron Christy M.Sc (N)

Professor, SRM Trichy College of Nursing

DOI: https://doi.org/10.51584/IJRIAS.2025.100700119

Received: 10 July 2025; Accepted: 16 July 2025; Published: 19 August 2025

ABSTRACT

Capgras syndrome is a rare neuropsychiatric disorder characterized by the delusional belief that a person or place has been replaced by an identical duplicate. We present a case of a 35-year-old male with schizophrenia who developed Capgras syndrome, believing that his wife was an imposter. The patient was treated with a combination of antipsychotic medication and cognitive-behavioral therapy, which led to significant improvement in his symptoms. This case highlights the importance of early diagnosis and treatment of Capgras syndrome, particularly in patients with schizophrenia.

Experts describe Capgras syndrome as a delusion of doubles. Delusions are an intense belief in something untrue. People with this syndrome think an identical duplicate (or double) replaced someone or something they love — including animals. They recognize the face but don’t feel emotionally attached; so, they assume that the person (or animal) is an imposter. They usually think the imposter has bad motives, which can cause someone with Capgras syndrome to get angry or even violent.

Keywords: Capgras syndrome, Cognitive-behavioral therapy, Delusional disorder, Neuropsychiatry, Schizophrenia

INTRODUCTION

Capgras syndrome (CS) is a rare psychological condition characterized by the delusion of doubles, where a person believes a familiar individual has been replaced by an identical imposter. We present a case of CS in a patient with a history of schizophrenia, highlighting the complexities of diagnosis and treatment^.(1)

Capgras syndrome (CS) is a psychological condition also known as the delusion of doubles. It is a misidentification syndrome also known as “imposter syndrome” or “Capgras delusion.” Sometimes, the person experiencing the delusion may believe an animal, object, or even a home is an imposter. CS can affect anyone, but it’s more common. Trusted Source in people assigned female at birth. In rare cases, it can also affect children^{. (2)}

People with this syndrome may, for example, accuse a spouse of being an imposter of their actual spouse. This can be upsetting for both the person experiencing the delusion and the person accused of being an imposter. ⁽³⁾

Capgras syndrome is a rare condition in which someone believes that their loved ones or others they know have been replaced with doubles or imposters. The belief is so real that nothing can correct this illusion.Capgras syndrome, or Capgras delusion, is named for the doctor who treated a patient with it nearly 100 years ago. You may also hear it called imposter syndrome, but it is different from the more common “imposter syndrome” that you may have heard about. ⁽⁴⁾

Since Capgras syndrome is rare, it’s hard to study. Most of what we know comes from doctors’ reports of individual patients. Some research shows that it’s more common among people with neurodegenerative conditions such as dementia; up to 16% of those with Lewy body dementia or Alzheimer’s also have Capgras syndrome. It’s also more likely in people with other brain conditions, such as Parkinson’s or epilepsy, in people who’ve had a stroke or a traumatic brain injury, or those with schizophrenia or bipolar disorder. One research estimates that people with schizophrenia and dementia make up 81% of all cases.

One study about Capgras syndrome used a health database of 250,000 people in the U.K. It found just 84 cases in that large pool. One common thread was that many people with Capgras syndrome also had other types of delusions. People with the condition also tend to be middle-aged, have had other mental health issues in the past, and are twice as likely to be women^.(5)

Case report

A 54 year old female with a 2-year history of schizophrenia, presented with a 6-month history of Capgras syndrome, believing her daughter was an imposter. She reported hearing voices supporting her delusional thinking and exhibited disorganized thought processes. Despite her husband’s efforts to reassure her, the patient’s delusions persisted, affecting her daily life and relationship. The patient’s symptoms included delusional thinking, aggression towards the perceived imposter, and disorganized thought processes. The patient’s symptoms worsened over time, prompting him to seek treatment. A thorough history revealed a complex interplay of psychiatric symptoms, highlighting the need for comprehensive treatment.

Causes of Capgras syndrome:

Capgras Syndrome Causes and Risk Factors

There are two systems at work in your brain when you see a familiar face. The central nervous system scans the features of the face. Then, the extended nervous system relays emotional information related to that face. Doctors still don’t know exactly how Capgras syndrome develops, but they think a broken connection between those two systems prevents normal face recognition.

A scientific review of 255 published cases of Capgras syndrome shows that researchers find it challenging to pinpoint the exact cause, which varies among cases. More research is needed to better understand Capgras syndrome, but scientists know that certain conditions may increase the risk of having this delusional syndrome.

Brain lesions

Many people with Capgras syndrome have one or more lesions or areas of damage on the brain. This includes those with dementia or Parkinson’s, which are degenerative brain conditions that can damage your brain. These lesions don’t have to be on the exact parts of the brain responsible for recognition. They can simply be on areas connected to them.

Substance abuse

Some people develop Capgras syndrome after using large amounts of recreational drugs, such as cocaine or cannabis, or heavily drinking alcohol.

Metabolic conditions

One study linked hypothyroidism (low thyroid levels in your blood) to Capgras syndrome.

Nutrient deficiencies

Another study showed that being short on vitamin B12 may also be a risk factor for Capgras syndrome.

Brain injury

The brain is a complex organ and traumatic brain injury (TBI) can lead to changes in brain function. It may affect your mood, balance, and memory, as well as other processes regulated by your brain, such as perceiving what your eyes see or listening and speaking. Some changes can be temporary and others permanent.

When the temporal cortex experiences damage, you can lose the ability to recognize familiar faces visually. TBI and concussion can lead Trusted Source to CS. This may be due to a disconnect between the temporal cortex and the limbic system, which regulates your emotions.

Prosopagnosia

People can also experience facial blindness, a condition known as prosopagnosia. Some experts suggest that the delusions of Capgras syndrome may occur because those with the condition cannot recognize Trusted Source familiar faces.

However, other researchers disagree that prosopagnosia is a cause of CS, according to a 2019 review of literature. This is mainly because not recognizing a person doesn’t necessarily make one think they are taken over by an imposter.

Neurological conditions

CS may occur with degenerative neurological conditions in which people experience dementia, such as Alzheimer’s disease (AD) and Lewy body dementia. These conditions can affect memory and can alter the person’s sense of reality.

Other neurological disorders associated with CS can include:

• Epilepsy
• stroke
• brain tumor
• Advanced parkinson’s disease

Schizophrenia and schizoaffective disorders

Schizophrenia, especially paranoid hallucinatory schizophrenia, can cause episodes of CS. Schizophrenia can also affect your sense of reality and can cause delusions. The same recent 2019 review also found that of 258 people diagnosed with Capgas syndrome, 32% had also been diagnosed with schizophrenia.

CS can also occur in those with schizoaffective disorders. These are mental health disorders in which a person primarily experiences symptoms of schizophrenia in addition to symptoms of mood disorders, such as depression or bipolar disorder.

The researchers also identified other conditions that co-occurred with CS. These conditions included:

• Psychosis
• Transient psychotic episodes
• Psychotic depression
• obsessive-compulsive personality disorder

Symptoms

• The primary symptom of CS is the delusion that familiar people have been replaced by identical doubles or imposters.
• Other symptoms can include being aggressive with the person suspected as the imposter. A minority of people with CS may become violent, and research Trusted Source has shown a connection between CS and homicide.
• Depending on the underlying cause, such as a neurological disease or schizophrenia, people with CS may experience other symptoms of the contributing condition.

Clinical Features

The patient exhibits delusional thinking, hallucinations, disorganized thinking

Diagnosis

The diagnosis of CS was made through a comprehensive psychiatric evaluation, including a review of the patient’s medical history and current medications. The patient’s symptoms met the criteria for CS, and other potential causes, such as Alzheimer’s disease and dementia, were ruled out.

Because CS is a rare condition, its diagnostic criteria are not included in the DSM-5, The Diagnostic and Statistical Manual of Mental Disorders, fifth edition.

Treatment

The patient was treated with antipsychotic medication and cognitive-behavioral therapy, which aimed to address the underlying schizophrenia and CS symptoms. The treatment plan also included reality orientation therapy to help the patient better understand their surroundings and reduce anxiety.

Capgras Syndrome Treatment

The right treatment depends on your situation. It may start with treating any physical or mental condition that could be causing Capgras syndrome. While this condition can be difficult to manage, proper treatment and good communication can lead to better outcomes.

Dementia drugs

Cholinesterase inhibitors, a type of drug used to treat dementia and Parkinson’s disease, ensure that there is enough of the hormone acetylcholine in the brain. This hormone is a chemical messenger that supports memory, language, and judgment. Donepezil (Aricept), galantamine (Razadyne), and rivastigmine (Exelon) are cholinesterase inhibitors that may reduce Capgras syndrome symptoms. Look out for side effects such as nausea, diarrhea, inability to hold your pee, muscle cramps or twitching, and weight loss. Starting at a low dose and working up may reduce some of these side effects.

Antipsychotics

Your doctor may recommend typical or atypical antipsychotics to treat Capgras syndrome delusions. Both work by blocking neurotransmitters, or chemical messengers, in your brain.

Typical, or first-generation, antipsychotics such as chlorpromazine, fluphenazine, haloperidol, and thiothixene block dopamine receptors. Atypical, or second-generation, antipsychotics such as aripiprazole (Abilify), olanzapine (Zyprexa), lumateperone (Latuda), quetiapine (Seroquel), and risperidone (Risperdal) block dopamine and serotonin receptors.

These medications may ease delusions and agitation. There are some possible disadvantages including movement disorders (especially if you’re being treated for Parkinson’s disease), heart and circulatory problems, dizziness, and sleepiness. Let your doctor know right away if you have any of these side effects while taking an antipsychotic.

Antidepressants

People with delusional disorders such as Capgras syndrome sometimes have depression, too. Antidepressants called selective serotonin reuptake inhibitors (SSRIs) can help. SSRIs are commonly prescribed and work by ensuring that enough serotonin is active in your brain. Examples are citalopram (Celexa), escitalopram (Lexapro), and fluoxetine (Prozac). Side effects may include headache, sexual problems, sleep disruption, weight changes, dizziness, nausea, and vomiting.

CS can be caused by brain or neurological damage. It may also occur due to another condition affecting the brain, particularly those that affect how the brain perceives or processes information or stores and retrieves memories

Treat underlying condition

Treatment aims to address the underlying cause. For instance, if someone with schizophrenia and CS has poor symptom control, treating the schizophrenia with antipsychotic medication can improve the CS.

These treatments may include:

• Medications like cholinesterase inhibitors, which boost neurotransmitters involved in memory and judgment, for dementia and AD
• Antipsychotics and therapy for people with schizophrenia
• Surgery or rehabilitation, if possible, for brain lesions or head trauma

Reality orientation therapy

• Reality orientation is a treatment for dementia that involves continuously orienting a person with dementia in the reality of their environment. This includes the time, place, and the people around them. This therapy may help people with dementia better understand their surroundings and feel less anxiety.
• For family and caregivers, practitioners recommend that if people undergoing reality orientation therapy express delusions, they should avoid arguing or correcting them. Instead, they suggest bringing the person back to the positive things in their environment to help them stay emotionally connected.
• According to a 2017 reviewTrusted Source, reality orientation can help with cognition and has behavioral benefits for those with dementia.

Behavior therapy

• To help people with CS overcome their delusions, mental health therapists may gently discuss the false beliefs while pointing out the evidence in favor of and against them.
• In addition, the ABC model in cognitive behavioral therapy is often used to help those affected overcome their delusions. It works by challenging delusional thoughts and beliefs to change how a person responds to them.

How to care for someone with Capgras syndrome

Caring for someone with CS can be emotionally demanding, especially if you’re the one they perceive as an imposter. To help someone with CS, here are some strategies to try:

• Enter their realm of reality when possible. It can help if you try to understand how terrifying it must be.
• Avoid arguing with them or trying to correct them.
• Help them feel safe. If you’re unsure what to do, you can ask the person what they need or talk with a healthcare professional.
• Acknowledge their feelings.
• If possible, have the “imposter” leave the room. If this is you and you’re the caregiver, let someone else take over until the episode is over.
• Rely on sound. If you know someone is prone to CS, you can make sure the first way they register your appearance is with sound. Greet them out loud before you see them when possible.

Capgras Syndrome vs. Imposter Syndrome

Some experts refer to Capgras syndrome as imposter syndrome. This is different from the more common “imposter syndrome,” which refers to when someone doesn’t believe they’re as capable as they are.

Capgras syndrome may be called imposter syndrome because those with the condition believe that imposters have replaced their loved ones. This symptom of Capgras is an actual delusion, while the other imposter syndrome refers to an internal belief about oneself.

Capgras Syndrome vs. Fregoli syndrome

Capgras and Fregoli syndromes are rare delusional disorders.

If you have Capgras syndrome, you believe your loved ones are replaced by imposters. Fregoli delusion is similar in that loved ones are involved. Except with Fregoli delusion, you believe people around you are familiar even though they’re actually strangers.

People with Fregoli syndrome may feel as though they are watching a play because strangers around them seem to change their appearance or wear disguises to appear like someone they know or love. Similar to Capgras syndrome, you may feel as though the familiar person in disguise is trying to harm you. You may also feel like they’re trying to trick you. Because of this, you may feel anxious, agitated, or paranoid.

Outcome

The patient’s symptoms improved significantly with treatment, and they were able to manage their delusions and aggression. The case highlights the importance of early diagnosis and treatment of CS, particularly in patients with schizophrenia

DISCUSSION

CS is a complex condition that requires a comprehensive treatment approach. Further research is needed to understand the underlying causes of CS and to develop effective treatment strategies. This case presentation aims to contribute to the existing literature on CS and provide insights into the diagnosis and treatment of this rare condition.

SUMMARY

A 35-year-old male with schizophrenia developed Capgras syndrome, believing his wife was an imposter. Treatment with antipsychotic medication and cognitive-behavioral therapy led to significant improvement

CONCLUSION

CS is a rare and challenging condition that requires a multidisciplinary approach to diagnosis and treatment. By presenting this case, we hope to raise awareness about CS and its complexities, ultimately improving patient outcomes. Early diagnosis and treatment of Capgras syndrome are crucial, particularly in patients with schizophrenia. A combination of antipsychotic medication and cognitive-behavioral therapy can be effective in managing symptoms.

REFERENCES

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2. “What Is Capgras Syndrome?” Cleveland Clinic, https://my.clevelandclinic.org/health/diseases/capgras-syndrome. Accessed 11 Jul. 2025.
3. “Capgras Syndrome: Causes, Treatment, and Caregiving.” Healthline, 1 May 2017, https://www.healthline.com/health/capgras-syndrome.
4. “What Is Capgras Syndrome?” Verywell Mind, https://www.verywellmind.com/capgras-syndrome-7100791. Accessed 11 Jul. 2025.
5. Koc, Aslı Enzel, and Cicek Hocaoglu. “What Is Capgras Syndrome? Diagnosis and Treatment Approach.” Anxiety Disorders – The New Achievements, IntechOpen, 2020. intechopen.com, https://doi.org/10.5772/intechopen.91153.