When the movie “Joker” was released last fall, it immediately stirred up a controversy about its portrayal of mental illness. The character of the Joker, played by actor Joaquin Phoenix, is depicted as having some kind of severe mental illness — one that triggers a series of violent acts after he is cut off from receiving anti-psychotic medications due to budget cuts.

“Severe mental health conditions, such as psychotic illnesses, remain shrouded in stigma and are consistently misrepresented and misunderstood,” wrote two doctors in an opinion piece for the Guardian soon after the film’s release. “Portrayals of mental illness in film can perpetuate unfounded stereotypes and spread misinformation.”

“One of the more toxic ideas that ‘Joker’ subscribes to is the hackneyed association between serious mental illness and extreme violence,” they add. “The notion that mental deterioration necessarily leads to violence against others — implied by the juxtaposition of Phoenix’s character Arthur stopping his medication with his increasingly frequent acts of violence — is not only misinformed but further amplifies stigma and fear.”

As those doctors (and many others at the time) pointed out, “Studies show this association is exaggerated and people with severe mental illness are more vulnerable to violence from others than the general population.”

You would think that most moviegoers would know better than to let a fictional film inform their perceptions about mental illness. But, as past research has shown, movies can exert a strong influence on such views.

A new study — one that specifically looks at how “Joker” influences attitudes about mental illness — underscores those earlier findings. It found that after viewing the film, people tend to express higher levels of prejudice toward individuals with mental illness.

The study was published earlier this month in the journal JAMA Network Open.

Study details

For the study, a team of New Zealand researchers randomly assigned 164 volunteers (average age: 30) to view either “The Joker” or a “control” movie, “Terminator: Dark Fate,” in a movie theater late last year. None of the volunteers had seen either movie before participating in the study, and each group was similar demographically in terms of gender, age, race and ethnicity.

“Terminator: Dark Fate” was chosen as the control movie because it has a similar level of violence as “The Joker,” but contains no depictions of mental illness.

Before and after seeing their assigned movie, the study’s participants filled out a validated questionnaire designed to measure people’s prejudice toward individuals with mental illness. The questions included ones on whether people with mental illness deserve our sympathy, whether they are unsafe to be around and whether they should be forced to undergo treatment.

The study found that, on average, people’s prejudices ticked upward after watching “The Joker,” but stayed essentially the same after watching the other movie. The upward swing was small — about 10 percent higher — but still significant.

No joke

This study involved a small group of people, all of whom lived in New Zealand. The findings may or may not be applicable, therefore, to other groups — including American moviegoers.

Also, the study assessed only attitudes, not behavior, toward individuals with mental illness.

Still, its authors believe the study’s findings are troubling.

“Beyond prejudice, associating mental illness with violence may erode support for policies that we know to be beneficial for those with mental illness (eg, integration into communities),” they write. “Additionally, Joker may exacerbate self-stigma for those with a mental illness, leading to delays in help seeking.”

And, yes, the authors believe this matter is no joke.

“In The Dark Knight, Joker asks, ‘Why so serious?’ One might level that question at us, arguing that Joker is nothing to be concerned with,” they write. “However, what this view ignores is the profound consequences prejudice has on those with a mental illness.”

FMI:  JAMA Network Open is an open-access journal, so you can read the study in full on the journal’s website.