By RICHARD A. FRIEDMAN, M.D.
The gunman, Adam Lanza, 20, has been described as a loner who was intelligent and socially awkward. And while no official diagnosis has been made public, armchair diagnosticians have been quick to assert that keeping guns from getting into the hands of people with mental illness would help solve the problem of gun homicides.
Arguing against stricter gun-control measures, Representative Mike Rogers, Republican of Michigan and a former F.B.I. agent, said, “What the more realistic discussion is, ‘How do we target people with mental illness who use firearms?’ ”
Robert A. Levy, chairman of the Cato Institute, told The New York Times: “To reduce the risk of multivictim violence, we would be better advised to focus on early detection and treatment of mental illness.”
But there is overwhelming epidemiological evidence that the vast majority of people with psychiatric disorders do not commit violent acts. Only about 4 percent of violence in the United States can be attributed to people with mental illness.
This does not mean that mental illness is not a risk factor for violence. It is, but the risk is actually small. Only certain serious psychiatric illnesses are linked to an increased risk of violence.