It never fails. After an incident like the shooting at the school in Newtown, Conn., the first instinct for many is to talk about gun control. But what about mental illness?

We've heard anecdotally that gunman Adam Lanza had some sort of mental disability or personality disorder, but we're without an accurate diagnosis from a medical professional about precisely what that condition was, its severity and thoroughness of treatment.

Still, the logical question lingers: Who but a mentally imbalanced individual could commit such a horrific act?

Statistically, the odds of such incidents occurring at your child's school are infinitesimal, but that's little comfort since, statistically, mass killings are occurring with increasing frequency. As David Brooks noted in the New York Times last summer, much of the 20th century saw perhaps one or two mass killings per decade. That number began rising after 1980: nine massacres in the 1980s; 11 in the 1990s; 24 in the last seven years while, simultaneously, the nation's overall homicide rate fell. Of the nation's 12 deadliest shootings, six have occurred since 2007.

Often the perpetrators were mentally disturbed. Is it more than coincidental that these incidents began rising after then-President Ronald Reagan cut federal funding for mental health care, leaving tens of thousands with no outpatient treatment or assistance to re-integrate with society? Has the continued rise in mass killings paralleled subsequent lawmaker decisions to routinely target mental health funding when budgets are crunched and money is tight?

Would it disturb anyone to know that last year, as the Hartford Courant noted, Connecticut Gov. Dan Malloy proposed drastic cuts to mental health and addiction services?

In Virginia, mental health care funding has fallen 9 percent since 2007, the year Seung-Hui Cho killed 32 people at Virginia Tech.

Following the Gabrielle Giffords shooting, the Justice Department crafted guidelines for an expanded firearms background-check system to keep guns out of the hands of criminals and the mentally ill. The plans were shelved amidst the politically charged congressional investigation of the Fast and Furious gun trafficking case and the intensifying election campaign.

Since 2009, states facing severe financial shortfalls have cut more than $4.3 billion in public mental health spending, according to the National Association of State Mental Health Program Directors. California cut more than $760 million.

A 1968 federal law prohibits gun sales to anyone declared mentally unfit. Tighter restrictions were added after the shooting at Virginia Tech. First, though, a court must declare someone unfit. Before that, however, persons must submit to treatment. They often don't because they won't, or because they can't because there's no money. Or there's a stigma. Or they're unaware they're even sick.

States do a terrible job of supplying mental health records to the National Instant Criminal Background Check System, the FBI database created in 1998 to help scrutinize a would-be gun buyer's history.

A 2011 survey by the National Center for State Courts found only half as many mental health records in the national database as existed in 42 of the 56 states and territories that responded.

According to the FBI, 1.1 million people are prohibited from purchasing a firearm because of their mental health status. Yet, from 1998 through 2010, only 6,103 attempted gun purchases at federally licensed dealers were halted because of mental illness restrictions. That's just 0.74 percent of all denials by the background check system.

Over the same period, nearly 600,000 gun purchases – roughly 73 percent of denials by the background checks – were prevented because of criminal records, including misdemeanor crimes and domestic-violence convictions.

A mentally ill person banned from buying a weapon can still circumvent the system where background checks aren't required: an unlicensed dealer at a gun show, a neighbor, the classified ads, or as in Newtown, a legal, gun-owning parent.

How much cutting of mental health budgets impairs the enforcement of laws prohibiting gun sales to the mentally unfit? Nobody knows. We seem not to care, either, because we see mental illness as a bogeyman. With no natural constituency in the electorate or support in the political structure, lawmakers steal from whatever mental health funds are available, knowing no one will complain. However, those dealing with mental health challenges in their own families struggle day and night with this problem.

The bogeyman isn't mental illness. It's society's unwillingness to confront it, destigmatize it, decriminalize it and treat it like a condition requiring expert medical attention, just like heart disease or diabetes.

As we see senseless acts of violence around the country committed by people with at least the hint of some type of mental difficulty, should we be taking money away from mental health treatment?

Guns don't kill people, they say, but we've seen far too many mentally disturbed individuals with guns kill people. An honest, grown-up debate about gun control is one worth having, but an honest debate about mental illness is one we've long neglected. At our peril.

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