Sudden Strangers: The Capgras Delusion

capgras delusion_angelo marcos blog

Imagine you’re having a conversation with a close family member.

Maybe you’re talking about work, or someone you both know, or an event in the news.

Things are all fine, except for a strange niggling sensation at the back of your mind.  Like a cat scratching at the back door, insisting on being let in.

You can’t quite place what is bothering you, but its there.

Shaking it off, you continue talking, all the while trying to ignore the ferocious scraping of those feline claws.

As the conversation goes on, you slowly – but unmistakably – come to a horrific realisation.

The person you’re talking to is an impostor.

They look like your family member down to the tiniest detail.  They even sound exactly the same.

But they’re an entirely different person.  You know it, even though you don’t quite know how.

Something just feels wrong.


This might sound like science fiction – or even a horror film – but it’s not.

It’s a recognised neuropsychological disorder known as the Capgras Delusion.

And it’s really, really weird…

The Condition: The Capgras Delusion (or Capgras Syndrome)

The Capgras Delusion was named after J M J Capgras, a French psychiatrist.  In 1923 he had a patient named Madame M, who was convinced that members of her family had been ‘swapped’ with impostors. Like an oil spill the delusion inexorably spread outwards from its source, smothering her friends and neighbours, and convincing her that they too had been replaced.

There have been numerous cases since.

Some sufferers will suddenly believe that their pet is merely a copy of their ‘real’ pet.  Other sufferers feel that their house – which they may have lived in for decades – is no longer theirs, but is a place that has been constructed to appear to be their home.

It may be an exact copy, but it’s a copy nonetheless.

The Cause of the Capgras Delusion

So what is going on here?

As with the phenomena of sleep paralysis and automatism,we have a collection of theories interspersed with as-yet unanswered questions.

The Capgras Delusion generally occurs in people who have suffered a traumatic head injury, or damage to brain cells for other reasons, for instance through dementia.

There have also been a number of cases documented in people who are suffering from complex mental health conditions such as schizophrenia. (Madame M above had a number of other mental health issues, so the Capgras Delusion didn’t – and generally doesn’t – happen in isolation, but rather alongside other conditions.)

The main theory is that the connections in the brain leading to the amygdala (which plays a primary role in the processing of emotional reactions) have been disrupted through the head injury/brain damage.  This then inhibits the emotional response we would ordinarily feel when viewing something familiar.

This lack of any emotional response then trumps everything else, including intellect.  It’s so unnatural to us as human beings that the only logical explanation is that the person or object is fake.  If that lady was your mother, you’d have had an emotional response.  But you didn’t, so she can’t be.

Interestingly, there have been a number of cases where the person suffering from the Capgras Delusion will think that someone is an impostor in person, but if they hear their voice without actually seeing them – for instance over the phone – then there is no problem.

Treatment of the Capgras Delusion

At present, there is none.

Some sufferers who have developed the delusion through a physical brain injury can sometimes ‘reconnect’ the pathways between perception and emotion. There have also been cases of sufferers with other mental disorders having the Capgras Delusion symptoms alleviated by medication taken for those other disorders.  However, for many sufferers there is nothing that can be done.

Trying to convince a person that they are mistaken often doesn’t work, especially in the cases of dementia or complex mental health conditions where logic and rational argument are largely ineffective.  Distraction techniques can be helpful, but this will vary from one individual to another.

Sadly, this means that the Capgras Delusion is therefore permanent in most cases.

Fortunately its also incredibly rare.

It does make you wonder just who is worse off though – is it the person who feels as though they are surrounded by impostors and the victim of some sinister plot, or is it the ‘impostors’ themselves, who have not only lost their family member to illness/injury, but will likely never be able to convince them that they are who they claim to be?

As Ralph Waldo Emerson once said, “Of all the ways to lose a person, death is the kindest.”

Sleep No More is my psychological thriller about a young woman whose vivid nightmares begin leaching into reality, causing her to doubt her own mind…

Click here to find out more


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s