The idea that all people with DID have alter-egos that look and act completely different, as depicted in "Fight Club," is false. Fox 2000 Pictures

Dissociative identity disorder, previously known as "multiple personality disorder," is a popular mental health condition to depict on TV and in film, but its media representation tends to be off-base.

The condition may affect up to 1.5% of the population and isn't necessarily obvious to outside observers, or even clinicians.

DID is a trauma-based disorder, and people with it are more likely to be victims of violent crime than perpetrators.

Here are the other myths about DID you need to stop believing now.

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"Dr. Jekyll and Mr. Hyde." "Fight Club." "Shutter Island." If you're a person who enjoy books, TV, or movies, you've probably come across some depiction of dissociative identity disorder, or perhaps heard of the diagnosis by its old name, "multiple personality disorder."

But while media representation of DID may lead you to think of people with "multiple personalities" as unstable and potentially violent, with distinct personas that they shift between, the truth is, much of that is exaggerated or just plain false.

In reality, DID is a very real disorder and public misunderstanding can be stigmatizing and harmful to the people who live with it. Insider spoke with mental health experts to debunk some common myths and misperceptions about DID.

MYTH: Dissociative identity disorder isn't real

Valarie L. Harris, a mental health clinician in Clarksville, Tennessee, told Insider this is one of the most common falsehoods about DID. It's also not exceedingly rare - DID may affect up to 1.5% of the population.

"DID is very real and often frequently missed by health care professionals. This is due to a lack of understanding, education, training, and experience," Harris said.

Part of this disbelief is rooted in the fact that many people have come to believe that DID appears in a very dramatic way that is obviously perceptible, which is not usually the case. While switching between "alters," as they're termed, does occur, it can be so subtle that it might be imperceptible to a stranger.

"Since most don't observe this, they come to believe it doesn't exist," Harris said, adding that people with DID are often misdiagnosed or mistaken for drug abusers, and that on average it can take a person with DID 10 years to be diagnosed correctly.

According to Kristina Hallett, a clinical psychologist based in Suffield, Connecticut, and an associate professor at Bay Path University, the idea that DID is fake or that patients are making up their reported symptoms is the most damaging myth out there. "This is so dismissive and undermining of the individual's experience," Hallett said, and it's not limited to laypeople, either.

"To this day, I still regularly encounter mental health professionals who are more skeptical and uninformed of the reality of DID than in regard to any other diagnosis," Hallett said.

MYTH: People with DID have distinct personalities they can switch into whenever they want

DID is a trauma disorder, not a party trick. "Dissociation" describes a "mental process of disconnecting from one's thoughts, feelings, memories, or sense of identity." Julie Barthels, a clinician based in Rockford, Illinois, said that dissociation happens on a continuum.

"Many survivors of trauma have dissociative experiences, such as being foggy and feeling slightly detached from reality," Barthels said. "Farther on the continuum are those who leave their body during the traumatic experience. Farther still are those with dissociative disorder who have alters or parts."

The important takeaway is that having alters isn't some wacky, out-of-left-field symptom; it's merely an acute version of a common response to trauma.

And Harris is quick to point out that people with DID can't always summon one of their alters on command. Rather, part of the therapeutic process is to help a person with DID connect with all their different alters or parts.

Most people with DID tend to wear the clothes that are comfortable and acceptable across alters, unlike the "United States of Tara" depiction.

MYTH: A person with DID has alters that look and act completely different

If you've ever seen "United States of Tara" (or even just the posters) or the movie "Split," you might think that a person with DID dresses vastly differently depending on which alter is present. This is more Hollywood than reality, however, according to Hallett.

"While there is often a differential preference in attire across alters, the individuals I know generally wear clothing that is comfortable and acceptable across their individual spectrum of alters," Hallett said. "There may be more of a discrepancy when the person is not aware of their DID, or has not developed good internal communication and cooperation."

Some people with DID do in fact have several highly characterized alters, each with their own names, ages, genders, races, mannerisms, and ways of speaking, but the "split personality" concept is a little misleading.

Rather than caused by a "splitting" of the consciousness due to trauma, "it's a failure to integrate into one identity," Harris said. All of us have different "parts" to our personalities, she added, "the difference is that we are more integrated than those with DID."

Dana Dorfman, a psychotherapist in New York City explained it simply: "People with DID do not have different personalities living within them. They are unable to integrate different emotional states into one cohesive sense of self."

MYTH: People with DID are crazy and violent

This is possibly the most unfair and harmful stigma associated with DID, but unfortunately, it's a fairly common misconception, according to Harris.

"While it is true that those with DID can have alters or parts that hold anger and may appear to be confrontational when challenged, this population is no more prone to violence or crime than the general population," she said. In fact, because people with DID are trauma survivors, they're more likely to be victimized themselves than the other way around.

When an angry or confrontational part does appear, Harris said it's merely a fear-based response meant to protect the individual from harm. Essentially, it's a defense mechanism.

Therapy for DID is just like therapy for any condition: dependent on the client's goals, strengths, and resources. Maskot/ Getty Images

MYTH: The goal of DID treatment is always integration of parts

There's a broad perspective that assumes the one and only goal of mental health treatment is to make a disordered person "normal." But no matter what their diagnosis, this is simply not always the case.

Barthels said that integration of alters or parts is often thought of as the only acceptable goal of DID treatment, but really, therapy for DID can take as many forms as therapy for anything else. "It requires that you understand your client's goals, strengths, and resources," Barthels said. "One client may desire integration while another may just want the parts to get along better."

Though it may seem odd to a neurotypical outsider, a person with DID may live a happy and full life even as they experience it through different alters.

MYTH: People with DID have tons of alters

While lots of narrative works depict people with DID as having 10, 20, or even over 100 alters, this is not always the case.

"The number of alters can range from one to many," Hallett said. And there isn't always rhyme or reason as to which people with DID have more or fewer alters.

"There are no specific rules of thumb or correlations to type or severity of abuse, or the legitimacy of the diagnosis," Hallet said. "It is also true that individuals with DID may not realize that they have DID, and even once the diagnosis has been made, that does not necessarily mean that the individual is aware of all internal alters."

MYTH: DID is a form of schizophrenia

DID and schizophrenia are "separate and significantly different diagnoses," according to Dorfman. One of these differences is that while schizophrenia has a genetic component, DID is a trauma-based disorder.

DID is also frequently conflated with borderline personality disorder, and while it's not uncommon for a person to have both diagnoses, they're not one and the same.

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