The film “Split” depicts a violent kidnapper with dissociative identity disorder. Experts say it’s not an accurate portrayal of people living with the illness.

M. Night Shyamalan is typically praised as a filmmaker who creates unusual stories, but his new movie “Split” has come under fire.

In the movie, a man with dissociative identity disorder (DID) kidnaps three girls, frightening and harming them.

While the star, James McAvoy, gives a dramatic performance as the villain, the movie has irked some medical professionals.

They say the film stigmatizes the disorder and may have a negative impact on people who have the condition.

Elizabeth Howell, a psychotherapist from New York, said the film raises the potential for dangerous attitudes to emerge and for people with the illness to be damaged.

Colleagues who have seen the film said it is not an accurate portrayal of someone with DID, she told Healthline.

“It is a disservice,” Howell said. “This is a common plot device. The serial murderer turns out to have DID. Why not have the plot be about a sociopath like Ted Bundy? Much more plausible.”

Between 1 and 3 percent of people in the world have DID.

The movie may imply that someone with DID could be violent, but experts say those people are more likely to hurt themselves than others.

In a statement about the movie, the International Society for the Study of Trauma and Dissociation (ISSTD) cited a soon-to-be-released study of 173 people with DID.

The researchers found that only 3 percent were charged with an offense, 1.8 percent were fined, and less than 1 percent were in jail over a six-month span. No convictions or probations were reported in that time period.

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DID used to be referred to as multiple personality disorder.

It is described by the National Alliance on Mental Illness (NAMI) as a disorder that forms when someone is trying to escape reality — often because they experience a traumatic situation such as abuse.

As a result, the people with DID shift between separate identities they form inside themselves to escape the trauma.

These personalities may have names, traits, mannerisms, and distinctive voices. When the person switches between personas, they experience memory gaps.

People with DID have out-of-body-like experiences. They may feel like voices are trying to control or possess them.

And they may also experience anxiety and depression.

Dr. Peter Barach, a clinical psychologist in Cleveland, told Healthline that most people are not diagnosed with DID right away because most mental health professionals are not trained to recognize the disorder.

Most adults with DID have been in the mental health system for several years. They may have received six or seven other diagnoses before DID is accurately identified.

Long-term therapy and medication are used to treat the disorder. Sometimes hospitalization is needed to stabilize a person with DID and ensure their safety.

“The psychotherapy helps the person to stabilize their symptoms and improve their ability to function in daily life,” Barach said. “Once the person is stabilized, the treatment works on processing the traumatic memories that interfere with daily functioning, self-esteem, relationships, and personal safety.”

“A large percentage of people with DID have made potentially lethal attempts to kill themselves,” he added. “The last part of treatment involves helping the ‘alters’ [parts of the self that experience themselves as separate people] to function in a more integrated and consistent way.”

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McAvoy told the “Today Show” that he watched video diaries made by people with DID and inquired about it with medical professionals.

However, he did not sit down with a DID patient while preparing for the role.

The ISSTD statement criticized those involved in the movie, in particular the filmmaker.

“With respect to Mr. Shyamalan’s ability to write and direct truly frightening movies, depicting individuals with this, or any other mental disorder, does a disservice to his artistic ability and to the over 20 percent of the population who, at some time or another, struggle with some form of mental illness,” the ISSTD statement said. “It acts to further marginalize those who already struggle on a daily basis with the weight of stigma.”

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Dr. Sheldon Itzkowitz, a New York-based psychologist and psychoanalyst, said he had not seen the movie — and doesn’t plan to.

“What concerns me is how the film may inadvertently demonize people who are truly suffering. DID is a disorder that has its etiology in the worst form of human suffering — the abuse of innocent children,” Itzkowitz told Healthline.

He said many of his patients with DID are highly functioning people whose friends and co-workers don’t know how much the person may be affected by their condition.

When films and stories “vilify and demonize mental illness in general, and DID in particular,” the viewer does not understand how hard it can be for that person to survive, he added.

As such, one of his colleagues views DID as a form of resilience. It is the “mind’s effort at trying to cope with overwhelming and terrifying trauma, often at the hands of people who were supposed to care for and protect the child,” Itzkowitz said.

Barach, who also had not seen the movie when he was interviewed by Healthline, said that the media is fascinated with mental illness as a cause of violence.

“Unfortunately, nearly all of the media depictions of DID are sensationalized. They sometimes depict treatment that would be considered unethical,” he added.

Barach said the movie reviews have led him to believe that the movie will not help society better understand DID. It will only add to the stigma of mental illness in our society.

“I wish the media would understand that people with DID suffer greatly and do everything they can to hide or ‘cover’ their symptoms, which they find embarrassing and often disabling,” he said.