Donald Trump has done it again. At the third Republican presidential debate Wednesday night, Trump managed to once more offend a large swath of people in one breath.

“I feel that the gun-free zones and, you know, when you say that, that’s target practice for the sickos and for the mentally ill,” he told CNBC moderators. “They look around for gun-free zones.”

Trump isn’t alone in this belief. In a Washington Post-ABC News poll released this week, 63 percent of participants—and 82 percent of Republicans—said mass shootings reflect problems in identifying and treating people with mental-health problems, while just 23 percent said they reflected inadequate gun-control laws.

But mental-health advocates, individuals who suffer from mental-health issues, and the people who support them likely bristled at his remarks. In the United States, one in four adults, or approximately 61.5 million Americans, experiences some form of mental illness in a given year, according to the National Alliance on Mental Illness, a nonprofit advocacy group. The mental-health community has long tried to rid the lexicon of language that, while once common, it now considers a driver of stigma against mental illness. She’s psycho. He’s gone mad. They’re sick in the head. A politician more concerned with public perception probably wouldn’t have used the term “sickos.” In fact, if anyone other than Trump had said it, there’s a good chance it would have been deemed a gaffe.

Decades of study and research into the diagnosis and treatment of mental health disorders has rooted out such terminology and generated more clinical, precise terms. Some of the new nomenclature spread into the public discourse and changed the way Americans speak. As my colleague Cari Romm wrote yesterday, “Words like mad have been used to mean insanity or dementia since the 1500s, but over the past couple centuries, it’s been used more as a general descriptor of a concept or personality than an indicator of mental illness”—a la March Madness.

But there’s much more to Trump’s remarks than the question of the “right” or “wrong” language. Trump’s claim that “they”—the sickos— specifically target areas that prohibit guns in order to carry out shootings is a common talking point among many Republicans and gun advocates. Mental-health reform, not gun reform, they say, is the way to solve America’s growing mass shooting crisis.

Trump’s claim also seems to rest on two big myths: that mental illness causes violence or crime, and that the presence of mental health can predict violence.

It has become standard practice to raise the question of the link between mental health and violence after a mass shooting. This makes sense: Few people can fathom a stable, sane individual committing such a horrid crime. “No matter what you do, guns, no guns, it doesn’t matter,” Trump said in August. “You have people that are mentally ill and they’re going to come through the cracks and they’re going to do things that people will not even believe are possible.”

Indeed, many mass shooters, most of whom are young men, are later determined to have exhibited signs of mental disorders. But extensive research has shown that only about 4 percent of violence in the U.S. can be attributed to people diagnosed with mental illness. Trump’s remarks suggest mental illness is the sole cause of violent acts, and not one factor among many. As with most things, context is important. As Mother Jones’ Mark Follman recently wrote in an exploration of how “to stop the next mass shooter”:

Legions of young men love violent movies or first-person shooter games, get angry about school, jobs, or relationships, and suffer from mental health afflictions. The number who seek to commit mass murder is tiny. ... That's why sizing up a suspect's current circumstances is crucial: Did he recently get fired from a job? Did he lose his kids in a nasty custody battle? Is he failing out of school or abusing drugs?”

The biggest risk factors for mass shootings—“basically, being an angry young man,” as New York magazine’s Jesse Singal puts it—are so widespread in the general population that it’s nearly impossible for anyone—psychiatrists, cops, parents—to predict whether someone will actually commit a mass shooting.

The reality of the connection between mental illness and violence is very different from the one delivered by Trump. People with severe mental illnesses are over 10 times more likely to be victims of violent crime than members of the general population, according to the U.S. Department of Health and Human Services. Research has shown that people with a mental-illness diagnosis are more likely to be discriminated against within the justice system, and are more likely to become incarcerated than healthy people, according to the Treatment Advocacy Center, a nonprofit advocacy group. In 2005, more than half of all prison and jail inmates in the United States had “a mental-health problem,” according to the Department of Justice.

“In this sense,” wrote doctors Jonathan Metzl and Kenneth MacLeish in an American Public Health Association paper on mental illness and mass shootings in February, “persons with mental illness might well have more to fear from ‘us’ than we do from ‘them.’ And blaming persons with mental disorders for gun crime overlooks the threats posed to society by a much larger population—the sane.”