When is a gun violence bill not a gun violence bill?

When it is legislation likely to get a political lift from concerns about mass shootings, but it is not specifically intended to address firearms issues.

Such is the case with the Mental Health Reform Act of 2015, a bill sponsored by U.S. Sen. Bill Cassidy that aims to overhaul the care and treatment of the mentally ill. Cassidy, a gastroenterologist from Baton Rouge, is a conservative Republican, but the bill’s lead co-sponsor is Christopher Murphy, a progressive Democrat from Connecticut; eight other co-sponsors include David Vitter, R-Metairie, and four additional Democrats.

The Senate Health, Education, Labor and Pensions Committee, which includes Cassidy and Murphy, held a hearing on the bill Thursday, and afterward, Cassidy and Murphy hosted a conference call with reporters.

“Lafayette, Louisiana, and Newtown, Connecticut, is what the two senators bring to the table,” Cassidy said at the beginning of the call.

In Lafayette in July, a man shot and killed two and wounded nine in a crowded movie theater. In Newtown in 2012, a gunman slaughtered 20 children and six teachers and staff members at an elementary school.

“The reality is that Congress’ attention is focused on mental health because of these unspeakable tragedies,” Murphy said. And, he said, “There’s no doubt that a better, more effective mental health system will result in fewer incidents of mass violence.”

But Cassidy and Murphy say their bill is not targeted at those incidents: It’s about improving treatment for the millions of Americans suffering from mental illness. In fact, Murphy said the sponsors are “walking a fine line” between leveraging the momentum for reform generated by the tragedies and contributing to the stereotype of the mentally ill as dangerous crazies — when, in truth, the mentally ill are much more likely to be victims of violence than perpetrators of it.

The mental health approach to firearms violence is the strategy favored by many gun-rights advocates, a corollary to the “guns don’t kill people; people kill people” mantra. That differs from the mainstream gun control response, which advocates restrictions on the sale and types of guns and where they are permitted.

“I understand that many of my friends are worried that moving on the mental health front will forsake doing others things that will reduce gun violence,” Murphy said. But he said he doesn’t think that’s a legitimate fear.

The main problems with the mental health system today, the sponsors said, are a shortage of capacity, a lack of coordination between treatment for mental health and physical health, and the stigma attached to mental illness.

The bill would provide more beds and outpatient facilities for the mentally ill by increasing reimbursement rates under Medicaid and Medicare.

It would break down regulatory barriers between treatment for mental and physical illnesses, and it would stiffen enforcement of laws requiring insurance companies to apply parity in providing for care of both kinds of illness.

The measure also aims to expand the use of treatment methods for mental illness that have a proven record of success.

Although their bill is not expected to move out of the Senate committee until next year, a similar measure is making progress in the House. On the House bill, Democrats have raised objections to a relaxation of privacy protections that bar doctors from communicating with an adult patient’s family members about the patient’s illness, to an increased potential for judges to mandate treatment and to changes in the administration of care by creating a new federal agency dedicated to mental health.

Cassidy and Murphy said their measure avoids some of those conflicts.

Another challenge for supporters of the legislation is finding a way to pay for it.

“It’s going to be hard to say you’ve made progress on mental health with a straight face if you haven’t put more resources into it,” Murphy said.

The cost has not yet been determined, but Cassidy said it could be covered by better allocating money already going to mental health: “We’re actually focusing dollars that are currently being spent where they can be spent more wisely.”

If successful, the sponsors said, the legislation could bring about the biggest reform to federal mental health policy in 50 years. The stakes are high, Cassidy said, because the effects of mental illness are far-reaching.

“It cuts across every demographic,” he said. “It just cuts into where we live.”

Gregory Roberts is chief of The Advocate Washington bureau. His email address is groberts@the advocate.com, and he is on Twitter, @GregRobertsDC. For more coverage of national government and politics, follow The Advocate Politics Blog at http://blogs.theadvocate.com/politicsblog.