The new idea to stop to gun violence—or at least one of the ideas that doesn’t have to do with limiting access to guns—is to improve America’s mental health system.

This is particularly popular among conservatives. The National Rife Association's Wayne LaPierre said last year that America needed a national database of the mentally ill because "The truth is that our society is populated by an unknown number of genuine monsters." Representative Mike Rogers, a Republican from Michigan and a former F.B.I. agent, responding to the Newtown shooting earlier this year, cautioned against gun control, saying, “What the more realistic discussion is, ‘How do we target people with mental illness who use firearms?’”

Obviously, to a certain extent, this is a distraction. You can’t kill a bunch of people with guns if you can’t get a gun, no matter how crazy you are. And there are not cries coming from mental health advocates for improvements to mental health services in order to prevent mass shootings. Support for this idea, then, seems mostly concerned with avoiding gun limitations, not actually improving psychological treatment.

Still, the gun rights advocates might be on to something.

PRIOR TO THE 1980S America had a robust and effective, if not particularly humane, method of keeping the mentally ill out off the streets: the state mental hospitals. Then we effectively eliminated that system, and almost immediately we saw a huge increase in mass violence.

The link is a little complicated, for sure. According to an article earlier this year from National Journal:

Numerous studies of the link between mental illness and violence suggest that improved screening and treatment will be of limited utility in reducing these kinds of killings. The reasons are myriad: Psychiatric professionals are not good at identifying people who will go on to commit acts of violence; many perpetrators of mass shootings had no contact with the mental-health system; and, even when the potentially violent are identified, treatment for mental illness is not always effective in preventing violent acts.

One of the largest studies of mental illness and violence, the 1991 National Institute of Mental Health’s Epidemiologic Catchment Area study, followed almost 18,000 people to discern lifetime predilection for violence. The study found that 16 percent of Americans with serious mental illnesses (schizophrenia and bipolar disorder) committed a violent act over the course of their lives. About seven percent of Americans without such illnesses committed violent acts. The rate of violence for people with serious psychological problems was higher, sure, but it wasn’t that much higher.

Most violent acts, though, are not senseless mass murders. Most violent acts are beatings or murders for revenge or punishment. But mass murders are something different.

AS MARK FOLLMAN WROTE at Mother Jones, of the 62 mass shootings that occurred in America between 1982 and 2012, “acute paranoia, delusions, and depression were rampant among them.” At least 38 of the shooters showed some signs of possible psychological problems before their rampages.

In the last 30 years we’ve seen a dramatic increase in mass shootings across America. We now have one every couple of weeks. It’s true that laws governing the possession of firearms are much more lenient than in 1980—30 years ago, eight states automatically licensed anyone without a criminal record to carry concealed weapons; now, 38 states do—but that can’t alone explain the huge increase in gun violence.

According to a 2012 article in Psychology Today:

Since 1980 ... there's a new sobering trend: Mass murders are on the rise. ... During the 20th century there were about one to two mass murders per decade until 1980. Then for no apparent reason they spiked. ... Since the year 2000 there have been at least 26, including the massacre in Aurora, Colorado.

No apparent reason? No, there’s a very apparent reason. There were two gun massacres in the two decades before Ronald Reagan took office, one in 1966 and one a decade later. Then there were, by some estimates, more than 30 mass killings during Reagan's time in office alone.

What happened? Well, with the 1981 Omnibus Budget Reconciliation Act, Washington cut federal mental health funding and converted the remaining money into block grants to the states.

Recently Charles Krauthammer, a former psychiatrist, wrote in National Review of an August event in which Aaron Alexis, the recent Navy Yard shooter, had called police from a Rhode Island hospital, saying that he was hearing voices. “Had this happened 35 years ago in Boston,” Krauthammer writes, “Alexis would have been brought to me as the psychiatrist on duty at the ER of the Massachusetts General Hospital. ... I probably would have administered an immediate dose of [antipsychotic] Haldol.” And then the young Krauthammer would have examined the patient, listened to his family and psychological history, and “if I thought he could be sufficiently cared for by family or friends ... I would have discharged him. Otherwise, I’d have admitted him. And if he refused, I’d have ordered a 14-day involuntary commitment.”

Why wouldn’t that happen today? Well, one reason, and the point of Krauthammer’s article, is that it’s much harder to commit people involuntarily to psychological hospitals. But the other reason is that such hospitals don’t really exist anymore, or at least they don’t operate how they used to. According to a 2011 report by the Bazelon Center for Mental Health Law:

Federal funding for mental health has been losing ground since the Omnibus Budget Reconciliation Act of 1981 replaced direct funding of community mental health agencies with a state block grant. Initially, appropriations for the block grant were significantly less than the previous funding for community programs and since 1981 block grant funding has fallen significantly in real terms. Between 1981 and 2005, state mental health spending, adjusted for inflation, grew only 0.9 percent each year. However, when also adjusted for population growth, State Mental Health Agency (SMHA) spending actually declined 0.2 percent annually.

The primary difference between 1978 and today, as far as mental health is concerned, has to do with the fact that the federal government has largely left the building. The 1981 law essentially slashed federal mental health and substance abuse allocations by 25 percent and converted them to block grants to the states disbursed with few strings attached. We didn't have a significant mass-shooting problem until then (though obviously lots of things other than mental health have changed since then, including a rise in structural income inequality).

IT'S IMPORTANT TO NOTE that changing the funding for mental health wasn’t just some heartless, anti-poor campaign designed as one of those supply-side experiments in domestic policy adjustment. This budget idea was bipartisan and came about after revelations of extensiveabuse of patients in state mental asylums throughout the United States in the 1960s and '70s.

A report by the National Alliance on Mental Illness refers to America’s mental health program as a “continuing crisis.” Today mental health services in America are particularly dependent on state funds, which mean mental health programs suffer even more during economic downturns.“Increasingly," according to the report, "emergency rooms, homeless shelters and jails are struggling with the effects of people falling through the cracks due to lack of needed mental health services and supports.”

To be sure, the reasons for the mass shootings are complicated and, while there’s a great deal of mental illness involved, the shooters are not always mentally ill, like Alexis, who demonstrated severe psychological problems that went untreated. But the state mental hospitals were part of a whole system of support for the mentally ill that has largely disappeared.

This is not to say that gun control and improved mental health are mutually exclusive policy solutions. Gun control alone, in fact, would dramatically reduce the number of people actually killed each year due to mass violence. There’s no question about this. Three years ago an unemployed man in Taixing, China, stabbed 28 preschool children while they were napping. They all lived. But if we want to look into the history here, and try and figure out why we’ve got so many mass shootings, the gun rights advocates aren't totally off-base.

Dramatic change in our mental health system is unlikely. This is because of, in part, the very real history of abuse and neglect in asylums and also because comprehensive mental health reform would be incredibly expensive, considerably more so than implementing strict gun control measures (which also won’t happen). But it’s time to stop ignoring the people who say that mental health matters here. They’re not just trying to avoid talking about guns. They’re actually focusing on something important.