One of the largest federal health agencies has instituted a near-total ban on gun violence research. Another has invested nearly $2 million to finance such studies over the past three years.

The divergent paths followed by the Centers for Disease Control and Prevention and the National Institutes of Health — both subject to the same congressional directive seen as trying to prevent all gun research — is attracting new attention as health researchers and other critics have put new pressure on the CDC to change its practices.

In 1996, Congress approved the Dickey Amendment, a measure inserted into an appropriations bill at the urging of the National Rifle Association, after the CDC produced a gun study that the advocacy group deemed unfair, and anti-gun. The amendment barred the CDC from funding research to “advocate or promote gun control,” and served as a brake on almost all gun violence research at the CDC. This happened even though many of the researchers within the agency thought that the language did not, in fact, prevent such studies.

More than a decade later, in 2012, Congress expanded the amendment to also include activities at the National Institutes of Health, a biomedical research facility with a budget three times that of the CDC. The NIH basically ignored it, as evidenced by the agency’s reaction to a call by President Barack Obama to expand gun violence research, issued in the weeks after the massacre of schoolchildren and teachers in Newtown, Connecticut. In response, the NIH asked for researchers to put forward proposals examining violence, and ultimately funded two focused on firearms.

As the Journal of the American Medical Association noted in a recent story, one study, conducted by University of California researcher Garen Wintemute, examines whether prior drug and alcohol convictions influence the rate of gun violence. The other, by University of Buffalo researcher Rina Eiden, looks at precursors of gun violence, such as gang ties.

In contrast, even after Obama’s directive, the CDC has forbidden its researchers from even discussing gun violence in the press, and limited its study of the issue to data collection — not actual research.

Experts say there are a few reasons why the CDC won’t invest in gun violence research in the same way the NIH has done.

The first is that unlike the NIH, the CDC has been subject to the Dickey Amendment for two decades, and early on was the target of a congressional move seen as an explicit warning. In 1997, Congress took $2.6 million from the CDC’s budget, the exact amount the agency had dedicated to studying gun violence in the previous year.

“There were even people who threatened to shut down the CDC Injury Center if there was gun violence research done,” says Linda Degutis, the former head of the Injury Center, in an interview with The Trace. “The NIH did not have the same kind of threat to their funding.”

Degutis adds that there tends to be less congressional scrutiny of the NIH than the CDC — because the former is seen as a place for medical research, developing cures. The CDC, in contrast, is more focused on prevention and implementation — areas that could come uncomfortably close to calling for tighter gun regulations, she says.

The NIH budget is also larger, and the agency has more discretion over how to spend it. In 2015, the NIH received $32.3 billion in funding, compared with the CDC’s $11.8 billion. If Congress does not allocate money to the CDC specifically for gun violence research, the agency would have to take money from some other program in order to fund it — and current leaders maintain doing so would not be possible.

As The Trace reported earlier this week, many former senior CDC leaders reject that notion. Mark Rosenberg, a founder of the National Center for Injury Prevention and Control, says the agency could reallocate funding for gun violence research “in the blink of an eye.”

[Photo: AP Photo/Mike Groll, file]