Nearly one in five Americans experience mental illness each year, according to the National Alliance on Mental Illness. But in an election cycle often dominated by worries about the economy and national security, mental health gets comparatively little exposure as a serious issue on the presidential campaign trail.
In this election season, the issue has been brought up most frequently when candidates have discussed mass shootings. Candidates on both sides of the aisle have stressed the need to prevent mentally ill people from acquiring guns, including Democrats advocating for gun control as well as Republicans arguing that the lack of treatment for mental health issues should be blamed for mass shootings rather than the gun industry.
The heroin epidemic has also provided an opportunity for candidates to link drug addiction and mental health, with candidates like Bernie Sanders and John Kasich arguing that the nation's prison system must stop being used as a substitute for treatment.
And mental health is also commonly mentioned in regards to the Department of Veterans Affairs, with many candidates promising to reform the agency and give veterans access to proper care, including for mental health.
It's even more rare for candidates to mention mental health as its own issue, one that isn't prompted by a national crisis or by a question from an audience member. Out of all the 2016 candidates, Hillary Clinton and John Kasich are perhaps the most vocal advocates for mental health care.
Clinton has called for mental health to be treated with parity to physical health issues. During the run-up to the Iowa caucus, Clinton frequently criticized the state's Republican governor, Terry Branstad, for closing two of the state's four mental hospitals.
Kasich, who is often attacked by conservatives for expanding Medicaid in his home state of Ohio, has argued that the move helped treat the mentally ill.
Bernie Sanders also occasionally speaks in his stump speeches about including mental health as a part of his health care plan, and has called for a "mental health revolution," usually in regards to making sure people are treated in light of the national conversation on mental health and guns.
And though it's not a part of his stump speech, Marco Rubio has talked about the stigma surrounding mental health issues when asked about it by voters.
Some candidates have taken a different approach and have joked about the issue. Cruz has said multiple times that he has "a lot of experience with mental health" issues because he's dealt with Congress, and Dr. Ben Carson has said that establishment Republicans have a "mental disorder."
Below is a selection of what each of the candidates have said about mental health on the campaign trail:
Dr. Ben Carson
"We do not provide the requisite support or finances for the mentally ill in this country, and we clearly have to address that because it has a domino effect. Every mentally ill person is not living in isolation, they affect other people who are around them, and there are a lot of facilities in this country that are sitting empty where we could very easily be providing the appropriate care," -January 4, Staten Island, New York
"There's mental health and substance abuse, both of which are incredibly expensive, heart wrenching, and in many ways, unaddressed in communities across our country. We're supposed to have parity, that means, if you have a mental health problem you're supposed to get taken care of just like if you had some physical problem. There shouldn't be any distinction. Because the more we learn about genetics the more we learn about the way the body works we know there are connections don't we. And so we have argued very hard to remove the stigma on mental health." - January 6, Henderson, Nevada
"It's sad to see the Democrats take a horrific crime and try to use it as an excuse not to go after people with serious mental illness or people who are repeat felons or criminals but rather try to use it as an excuse to take away the Second Amendment rights of law abiding citizens." June 19, Red Oak, Iowa
"When you help people who people normally in politics run over, people notice. Here's what I mean. You know how easy it is in politics to ignore the resources you need for the mentally ill? It's really easy. they don't have a lobby, they don't have any power. so when you tend to them, when you make sure that you treat them right, that's a great thing. And people notice. And they respect it. And so don't ever ignore those that don't have the power." - January 19, Concord, New Hampshire.
"There's a stigma associated with it. We have to remove it. Mental health is no different than any other disease. You didn't do anything wrong. It's nothing to be ashamed of. It happens. And people at any age who have it deserve access to treatment, quality treatment, quickly. And we, as a society, should not stigmatize it." January 5, Ft. Dodge, Iowa
"I think we need a revolution in mental health. And that revolution is about making sure that the many thousands of people who are walking the streets of America today who are suicidal or homicidal get the help they need, and they get it now, not two months from now." - December 6, CBS's Face The Nation
"We have a tremendous mental health problem. We're closing places all over the world. All over the country they're closing. Nobody's doing anything about that. All they want to do is blame the guns. And it's not the gun that pulls the trigger." - January 3, CBS's Face The Nation