Capgras syndrome is a rare condition where someone believes that a loved one is not who they say they are. They believe this person is an imposter or a double.

People with Capgras syndrome usually believe the supposed imposter has bad intentions. This can lead to aggression or violence, sometimes putting other people at risk.

The exact cause is unknown, but people with Capgras syndrome often live with other mental health conditions, such as schizophrenia or dementia. The person may be at risk of harming themselves or others.

If you suspect you or a loved one is experiencing this phenomenon, it’s important to talk with a mental health professional who can advise on treatment and provide support.

Capgras syndrome, also called Capgras delusion, is a condition in which people mistakenly believe their spouse, parent, child, or another person has been replaced by a double. They may recognize the face but don’t feel the bond of emotional connection. As a result, they conclude the person is an imposter.

Capgras is a delusional disorder.

Fregoli delusion is another kind of delusional disorder, where you believe people around you are familiar even when they’re strangers.

Capgras syndrome isn’t a stand-alone diagnosis in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). However, it can be a feature of other conditions with DSM-5 diagnostic criteria, such as schizophrenia or schizoaffective disorder.

Capgras syndrome is a rare condition and signs vary between people. One feature appears to be that the supposed imposter is someone with close emotional ties to the person, such as a parent or spouse.

Signs and symptoms can also differ depending on what’s causing the syndrome in a particular person. Some symptoms might include:

People with Capgras syndrome often believe that the supposed imposter has harmful intent. They may therefore become hostile toward the person they think is a double.

What causes Capgras syndrome isn’t exactly known.

In 1979, researchers first hypothesized that the syndrome resulted from structural brain differences. According to research from 2016, scientists are still trying to determine what brain differences lead to Capgras delusion.

A 2021 article stated that the current research classifies Capgras as a neurologic and psychiatric condition. Early research from the 1980s connected Capgras with brain lesions, but newer findings suggest the causes are more complex.

There are several theories about how the brain works when someone experiences Capgras syndrome. One is that there’s a miscommunication between the parts of the brain responsible for facial recognition and emotional processing.

A 2019 article looked at 255 reported cases of Capgras delusion and concluded that the nature of the delusion was variable. The authors said it would be challenging to work out a definitive cause.

Capgras syndrome is associated with several conditions. The most common is schizophrenia or schizoaffective disorder. It may also be a feature of dementia.

Some conditions that may coexist with Capgras syndrome include:

Approximately 16% of people with Alzheimer’s disease experience Capgras syndrome. Of those with Lewy body dementia, as many as nearly 28% have Capgras.

A 2019 review found a strong association between Capgras syndrome and aggression. The majority of case reports reviewed in that study showed no propensity for violence, the connection between the condition and aggressive behavior was significant nonetheless.

There are risk factors for violence or aggression toward the “imposter.” These include:

  • the presence of longstanding delusions
  • a history of aggressive behavior, particularly in those with schizophrenia or dementia
  • substance use
  • social isolation or withdrawal

Capgras syndrome is also linked with self-harm behaviors.

Capgras delusion can impact the person’s ability to maintain employment and participate in society, creating financial and emotional challenges for them and their loved ones.

Treatment for Capgras syndrome typically starts by addressing the underlying condition. Because of the risk of violence, a mental health professional will likely perform a violence risk assessment.

A person with Capgras syndrome may receive one or a combination of therapies, such as:

Someone who exhibits violent or self-harming behavior despite these interventions may benefit from a hospital stay.

Although family members may wish to handle the situation independently, it’s important to feel safe. Loved ones of someone with Capgras syndrome should seek help from a medical or mental health professional if they feel unsafe or overwhelmed.

If you’re looking for a therapist but aren’t sure where to start, check out Psych Central’s How to Find Mental Health Support resource.

Capgras syndrome, or Capgras delusion, happens when a person believes a loved one has been replaced by a double.

Schizophrenia and dementia are two of the more common underlying conditions experienced by those with Capgras syndrome. Researchers still don’t know if the phenomenon is because of differences in brain structure, brain injury, psychology, or a combination of these.

Treatments are available for this condition. These therapies include antipsychotic medications, antidepressants, and CBT. In cases of self-harm or violence despite treatment, the person may have to stay in a hospital.