President Trump and Republican lawmakers spent Thursday pointing to a void in the nation's mental health as a cause for Wednesday's school massacre, killing 17. But those who study mental disorders say they do not lead to mass shootings.

"Most Americans with mental illness are not violent," said Alex Azar, the acting director of the Centers for Disease Control. "In fact, they're more likely to be victims of crimes themselves," he said.

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Only three percent of people with serious mental illnesses contribute to violent crime, according to a 2016 report by the American Psychiatric Association. It found each year, mass shootings by the mentally ill make up less than one percent of all gun-related homicides.

"It's not this simple issue," said Dr. Jonathan Metzl of Vanderbilt University. He has studied the mass shooter mentality, citing shooters have many motivations. He insists making the country's latest mass shooting a mental health issue is misguided.

"To reduce the problem just to mental illness really does a disservice to our attempts to understand what happened," he said.