Maybe Oregon Shooting and Others Aren't About Mental Illness

Regardless of whether you believe in gun control, there is a widespread belief that mental illness is behind mass shootings. After all, who but a crazy person would start killing people, as happened Thursday at Oregon's Umpqua Community College?

Some researchers believe that the link between mental illness and mass shootings is tenuous. They note that the vast majority of the mentally ill don't exhibit violent tendencies, and even among mass shooters only a minority exhibited signs of extreme mental distress.

"If we were able to magically cure schizophrenia, bipolar disorder, and major depression, that would be wonderful, but overall violence would go down by only about four percent," Dr. Jeffrey Swanson, a professor of psychiatry at Duke, told ProPublica last year. He notes a 2001 study of mass shooters that found three out of four had no psychiatric history.

Efforts aimed at keeping the mentally ill from guns have done little to lower the overall crime rate. In 2001, Connecticut added patients who had been involuntarily committed to mental institutions to the National Instant Criminal Background Check System. The result? Violent crime among those persons dropped by over 50 percent, but since they constitute such a small percentage of the criminal population only 14 violent crimes were prevented—not 14 mass shootings, just 14 violent crimes. That's good as far as it goes, but Swanson notes: "It's like if you had a vaccine that was going to work against a particular public health epidemic, but only seven percent of the people got the vaccine. It might work great for them, but it's not going to affect the epidemic."

A better approach, says Swanson, is taking guns out of the hands of those who have demonstrable violent behaviors instead of the very high bar of having been committed. "Some of that can be voluntary: I have colleagues who are psychiatrists. When they see patients with serious depression, they counsel them about the danger of having a gun in the house. They have a conversation with family members," Swanson says. "You can do a lot without invoking law, by talking to people about harm reduction and locking up guns. Getting family members to voluntarily store guns somewhere else."

A recent study by Jonathan M. Metzl and Kenneth T. MacLeish of Vanderbilt University found in a review of the literature on gun violence that the mental health connection was dubious.

"Of course, understanding a person's mental state is vital to understanding his or her actions. At the same time, our review suggests that focusing legislative policy and popular discourse so centrally on mental illness is rife with potential problems," they write.

The authors' study suggests that a reductionist link between mental health and mass shootings is too simplistic. Most mentally ill persons are more likely to be victims of crime, and so many never commit violence. The common post-shooting cry that more resources should go toward dealing with mental illness misses the point. So many factors seem to go into mass shootings—age, alcohol and drug use, social isolation, the availability of guns, whether the shooter knows the victims (usually they do) and mental illness—that the problem needs to be addressed in its totality.

Swanson would like to see more focus on those who have exhibited violence rather than those who have mental illness. "If someone has a history of any kind of violent or assaultive behavior, that's actually a better predictor of future violence than having a mental health diagnosis," Swanson told ProPublica. "If someone has a conviction for a violent misdemeanor, we think there's evidence, they ought to be prohibited" from owning guns.

Of course, there's nothing wrong with improving access to mental health treatment. It has its own benefits for patients and their families. But the evidence suggests the idea that mental health treatment alone is going to reduce the number of mass shootings is overly optimistic. That seems to be true overseas, too. A British study found little causal relationship between mental illness and violence.

A few years ago, it was popular to blame video games or films or rap music for violence. National Rifle Association chief Wayne LaPierre pointed to (rather dated) films like 1994's Natural Born Killers after the 2012 slaughter of elementary school students in Newtown, Connecticut as the kind of violent art that inspires killings. The evidence that violent entertainment causes violent behavior is questionable. Killers may play Grand Theft Auto, but so many more peaceful people like killing pixelated cartoon figures that it's not really a useful variable. It's the difference between causation and correlation, as the social scientists put it: The sun doesn't come up because the rooster crows, even if they happen at the same time.