TAMPA, Fla. – President Donald Trump said Monday that the mass shooting that unfolded inside a Texas church Sunday was not “a guns situation,” but rather an issue with mental health.

“I think that mental health is your problem here,” Trump told reporters at a press conference during his visit to Tokyo. “We have a lot of mental-health problems in our country, as do other countries. But this isn’t a guns situation.”

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And indeed, it appears most Americans feel the same way.

National opinion polls like this one show wide agreement that gun violence—and more specifically mass shootings—reflects problems in identifying and treating mental health.

But psychologists say research shows otherwise, that the vast majority of people with mental illness are not at all violent.

One in five Americans experiences a mental illness—that’s nearly 44 million people.

And while it is true that some of the country’s worst mass shooters were found to have a history of mental illness—like the Colorado theater gunman, James Holmes or the Virginia Tech shooter, Seung Hui Cho, whom a judge ordered to get treatment—experts argue most such killers do not exhibit classic forms of mental illness.

An estimated 4 percent of violence against others is caused by symptoms of serious mental illness, like schizophrenia, according to this research.

Less than a quarter of indiscriminate mass shooters have been found to have psychotic disorders, according to data compiled by the Treatment Advocacy Center.

“I think by broadening and generalizing that this is a ‘mental health issue,’ we take away from the fact that everyone has mental health issues,” said Dr. Stacey Scheckner, a Tampa-area psychologist, who says broad generalizations will only further stigmatize mental health.

“Saying that if you have a mental illness, you’re violent is not an equation. That is not two-plus-two-equals-four.”

Scheckner says it’s important to know that mental illnesses cannot be lumped together with an established set of symptoms that leads to violence. She argues individuals who commit mass murder are motivated by something else and that treatment, no matter how available, might not be a viable solution.

“People who are prone to mass shootings have a personality disorder instead of a mood disorder, think a sociopath, narcissist,” she said. “Those type of people are not going to want to get help, they think they’re right, even if we had all the funds in the world.”

Michael Stone, a forensic psychiatrist at the Columbia College of Physicians and Surgeons who the Washington Post reported maintains a database of more than 300 killers, most of them shooters of four or more people, found that just about two out of ten mass killers were suffering from serious mental illness.

“The rest had personality or antisocial disorders or were disgruntled, jilted, humiliated or full of intense rage,” the Washington Post went on to report. “They were unlikely to be identified or helped by the mental-health system, reformed or not.”

Despite the president’s claims, it is still undetermined if the shooter, who investigators have identified as 26-year-old Devin P. Kelley, showed any signs of mental illness.

Kelley, however, was discharged from the Air Force several years ago for assaulting his spouse and a child, the Air Force said.

The attack happened in South Texas on Sunday morning when Kelley, dressed in black tactical-style gear and armed with an assault rifle, opened fire inside a Baptist church in a small community, killing 26 people and wounding at least 16 others in the deadliest mass shooting in state history.

The Associated Press contributed to this story.

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