The Neurological Disorder You Don't Know About

For most people, the midcentury B-movie Invasion of the Body Snatchers is exactly that: a movie. For people with Capgras syndrome, however, the classic tale of a California town whose residents are replaced by impostors one by one is more than just a fun way to spend 90 minutes; it's a terrifying reality. Of course, the real-world version features significantly fewer alien invasions than Hollywood's interpretation, but that tends to be true of most things. If there's one thing producers love more than LGBT erasure and mountains of cocaine, it's alien invasions.

But I digress. By now, you're no doubt wondering what the heck I'm talking about — what is Capgras syndrome? Although the neurological disorder, sometimes known as Capgras delusion, has a number of complicated causes, the actual symptoms are simple. Individuals with Capgras delusion suffer from delusional misidentification leading them to believe that people around them have been replaced by impostors — exact doubles designed to perfectly mimic the original.

It sounds like the plot of a particularly outlandish episode of House, but for the individuals suffering from the disorder, Capgras syndrome is all too real. In fact, although it used to be considered extremely rare, researchers now believe it may be more common than previously thought. Let's take a look at some things you may not have known about this fascinating, difficult condition.

What Are the Symptoms?

Capgras syndrome stems from a variety of causes, as we'll see later, but the symptoms are always the same: A pervasive feeling that those around you have been replaced by identical impostors. This delusion centers around the sufferer's loved ones, including spouses, siblings, and pets; it even extends to the patients themselves, who see a doppelganger instead of their reflection. As a result, people with Capgras syndrome often remove mirrors from their living spaces in an effort to avoid their reflection. According to the Pittsburgh Post-Gazette, patients are capable of recognizing themselves, but they feel no emotional connection to the person in the mirror:

In his room at the Western Psychiatric Institute and Clinic, Joseph looked in the mirror. There, he saw a man he had never seen before... "Do I look different?" he asked people around him. "Am I still the same person?"

Interestingly, the delusion is restricted to sight — someone with Capgras syndrome can recognize their mother's voice on the phone, for instance, but they can't reconcile that voice with the woman who walks into view claiming to be their mother.

What Causes Capgras Syndrome?

Like many neurological disorders, Capgras syndrome is often caused by traumatic brain injury or conditions that affect the brain, such as dementia, Alzheimer's, and schizophrenia. However, research has indicated that it may be possible to induce the delusion in healthy subjects using psychotimetic drugs. (Is that not the most mad scientist-y experiment you've ever seen?)

What these causes all have in common, of course, is that they affect the brain, leading researchers to hypothesize that Capgras syndrome is caused by a disruption of the pathway between visual stimulation and emotional responses. In healthy individuals, a familiar face activates visual pathways in the temporal lobe as well as emotional pathways in the amygdala, which combine to create a sense of attachment. In people with Capgras syndrome, scientists believe that this connection has been severed. It should be noted that this is different from face-blindness, or prosopagnosia — with Capgras syndrome, patients are able to recognize that someone looks like their sister, but they don't feel any emotional response. Therefore, they conclude that the person simply can't be their loved one.

How Common Is It?

Although Capgras syndrome was believed to be extremely rare in the decades since its discovery by Joseph Capgras in the early 20th century, researchers now believe that it may be more common than previously thought. On the other hand, it's still pretty rare, so don't start freaking out just yet.

Is There A Cure?

Unfortunately, there's no "cure" for Capgras syndrome. If it was caused by a brain injury, there's a chance that the brain could fix itself, so to speak, by re-establishing pathways disrupted by the trauma. However, if it stems from psychological disorders such as dementia or psychosis, there is little modern medicine can do other than treating the main cause and hoping for the best.

How Do You Treat Someone With Capgras Syndrome?

Capgras may be rare, but there's a chance you may come across someone with the disorder in your lifetime, and it helps to be prepared. Like many psychological disorders, many people's instinctive reactions (trying to reason with the patient, arguing, expecting progress every day) are actually counterproductive. Psych Central has an in-depth discussion of how to react to Capgras syndrome here, but the highlights are this: Don't correct them, do try to understand their situation, and do focus on the positives when you can.

There you have it! All you need to know about one of the most fascinating, tragic disorders discovered in the last century. Now if you'll excuse me, I'm off to rewatch Invasion of the Body Snatchers.

Image: Jake Stimpson, Ellen Munro, Helga Weber, Dee Ashley/Flickr