The story of Tuesday’s Germanwings plane crash, which killed all 150 people onboard, has only gotten more tragic as more details emerge. On Thursday, audio from the plane’s black box showed that co-pilot Andreas Lubitz apparently locked the commanding pilot out of the cockpit, and seems to have intentionally crashed the plane. On Friday, news coverage turned to speculating about Lubitz’s mental state, in an attempt to answer the haunting question that floats above the wreckage of every man-made tragedy: “How could someone have done this?”

"Everything is pointing towards an act that we can't describe: criminal, crazy, suicidal,” said French Prime Minister Manuel Valls, according to Agence France-Presse.

Criminal. Crazy. Suicidal. That Valls would group those three words together says a lot. It hints at a dangerous equivalence. Suicidal doesn’t equal homicidal. Criminal doesn’t equal crazy. And crazy is an unkind thing to call someone who’s suffering.

What evidence we have of Lubitz’s mental health or lack thereof is still scant. The New York Times reports that he “had a medical condition that he hid from his employer.” Investigators found a doctor’s note at his home that would have excused him from work on the day of the crash, as well as another, ripped-up, note. The BBC says German media are reporting that Lubitz’s training was interrupted in 2009 so he could receive treatment for depression. While his employers at Lufthansa airlines have confirmed he took time off, they have not said why.

Yet Friday morning’s headlines were frantic about the possibility that Lubitz could have been depressed. The Daily Mail, ever over-the-top, went with: “Mass-killer co-pilot who deliberately crashed Germanwings plane had to STOP training because he was suffering depression and 'burn-out.'” CNN’s homepage blared “Unfit to Work” in all-caps.

“It’s kind of natural to say ‘This just has to be deeply crazy,’” says Jeffrey Swanson, a professor of psychiatry and behavioral sciences at Duke University who studies violence and mental illness. But people who commit mass murder “are really atypical of people with mental illness,” he says. “The vast majority of people with schizophrenia, bipolar disorder, or major depression are not likely to do anything violent and never will.”

By one measure, only 5 percent of violent crime is actually attributable to mental illness. For depression specifically, a study of more than 47,000 people in Sweden found that 3.7 percent of men and 0.5 percent of women diagnosed with depression committed a violent crime, The Guardian reported. In the general population, those numbers were 1.2 percent for men, and 0.2 percent for women. Depression is a risk factor, then, but a very small one.

“There’s this disconnect, but that becomes a prism through which we see these problems,” Swanson says.

People are understandably upset by this portrayal of Lubitz, which makes the leap to equating mental illness and violence, using only the very limited evidence of this one situation. Masuma Rahim, in an op-ed for The Guardian, worries that news reports blaming depression could “further [demonize] those with mental illness.”

To conclude that his role in the crash was the automatic consequence of any history of mental illness would be irresponsible and damaging. There has been no suggestion that males should be prohibited from becoming pilots, that Germans are unfit to fly, or that 27-year-olds should not be let loose in the cockpit. Only one factor has been picked over: Lubitz’s mental health.

This is an all-too-familiar progression. Within the past few years alone, the Newtown shooting, the Aurora shooting, and the Navy Yard shooting all come to mind, for how quickly the conversation turned from the killers’ actions to their minds. The impulse is understandable. Mental illness can be treated, and in the face of horror, people want action. What can we do to prevent this from ever happening again?

“A horrifying act like this, on the face of it, is deeply irrational, it’s terrifying and it seems unpredictable,” Swanson says. “It’s everything that we don’t want our everyday life to be. We want everyday life to make sense. We want to be able to predict what’s going to happen when we get on a plane, get in a car, or go to a shopping mall.”

Now, in the wake of the Germanwings crash, people are calling for better mental health screenings for pilots. Better screenings, earlier intervention, improvement of the mental health system all-around—these are noble goals. But unfortunately, the impact they could have on preventing future violence is probably small.

“If we were to take schizophrenia, bipolar disorder, and major depression…if I could wave a wand and magically cure those three illnesses, the overall amount of violence in society—any minor or serious violent act, pushing and shoving or using a weapon—would go down by about 4 percent,” Swanson says. “Ninety-six percent of it would still be there.”

Though the link between violence and mental illness is slight at best, the public tends to believe otherwise. One report found that “between 1950 and 1996, the proportion of Americans who describe mental illness in terms consistent with violent or dangerous behavior nearly doubled.” This attitude persists today. A 2013 Gallup poll conducted shortly after the Navy Yard shooting found that 48 percent of people blamed the mental health system “a great deal” for mass shootings. Thirty-two percent blamed it “a fair amount.”

And it paints an incomplete picture to look at mental illness alone, without all the other factors at play. For example, studies by Seena Fazel at the University of Oxford have found that people with substance abuse problems in combination with mental illness are more likely to be convicted of violent crime than people with mental illness alone. And Swanson says he’s done research on three big risk factors, one of which is substance abuse. The others are being a victim of violence while young, and witnessing violence in your surroundings.

“It’s important not to use this direct causal language,” he says. “When there is a terrible incident and it turns out the perpetrator has a mental illness, what you find is that the general public and media seize upon this as the master explanation—‘That’s what it was! Now we know. Of course.’ Maybe that’s a contributing factor, but violent behavior is a very complicated human behavior that is almost always caused by a whole lot of factors interacting in complex ways.”

And “violent behavior” is a vague term, that can encompass anything from punching someone in the face, to purposefully crashing a plane full of people. The two things are more different than they are alike. The world is now faced with the latter. Wanting an explanation, something to blame, is a human reaction to atrocity. “Something was wrong with this man” is an answer to hold onto. It can soothe the pain of not-understanding, if not the pain of loss.

“But if you generalize that kind of view toward all the people diagnosed with and struggling to recover from serious mental illness, we end up treating people with scorn and seeking distance from them," Swanson says. Something people do too much already.