WASHINGTON — In the days after the Newtown, Conn., massacre, the one thing opponents and advocates of gun control agreed on was the need to address deficiencies in the mental health system so that killers like Adam Lanza would stop slipping through the cracks.
Since then, however, with Congress consumed by issues like background checks and a ban on assault weapons, there has been comparatively little focus on how American society deals with mentally ill people.
But quietly, lawmakers have been working on several plans that would lead to some of the most significant advancements in treating mental illness in years, proponents said. All stand a good chance of being in the final gun-control bill the Senate is now taking up.
The legislation would, among other things, finance the construction of more community mental health centers, provide grants to train teachers to spot early signs of mental illness and make more Medicaid dollars available for mental health care.
There would be suicide prevention initiatives and support for children who have faced trauma. The sponsors of one of the bills estimated that an additional 1.5 million people with mental illness would be treated each year.
The issue is one of the more distinguishing — and unnoticed — aspects of the gun-control debate, which has been stymied by partisan squabbling.
Unlike other initiatives that the Senate is likely to vote on — expanded background checks, a restriction on high-capacity ammunition magazines and a ban on certain semiautomatic weapons — mental health unites lawmakers Republican and Democrat, urban and rural, even those with safe seats versus those who may face competitive races.
One bill, sponsored by Senator Debbie Stabenow, Democrat of Michigan, has been joined by some of the Senate’s most conservative members who are strongly backed by the National Rifle Association, including Marco Rubio of Florida and Roy Blunt of Missouri, both Republicans.
Another bill, which has the support of Senator Tom Harkin, Democrat of Iowa, and Senator Lamar Alexander, Republican of Tennessee, unanimously passed a Senate committee this week, something that could hardly be said about any of the gun legislation.
“This is a place where people can come together,” Ms. Stabenow said. “As we’ve listened to people on all sides of the gun debate, they’ve all talked about the fact that we need to address mental health treatment. And that’s what this does.”
Indeed, some Republicans have used mental health care as a political refuge while pressure to act on gun laws built. John Cornyn of Texas, the No. 2 Senate Republican, who has not wavered in his opposition to tighter gun laws, met with families of Newtown victims but said he came away believing they wanted to attack mental health problems above all else.
“This is actually something we can and should do something about,” Mr. Cornyn said. “We need to make sure that the mentally ill are getting the help they need.”
Advocates for better mental health services said that many of them were initially uneasy about seizing on an event as tragic as the Connecticut school shootings. But they came to believe that the current time was the best opportunity for real change, and that they might not get another one for a while.
“This is our moment,” said Linda Rosenberg, the president of the National Council for Community Behavioral Healthcare. “I hate the connection between gun violence and the need for better mental health care, but sometimes you have to take what you can get.”
President Obama has also joined the effort. His budget includes $130 million for programs that would help detect mental illness in young children, train educators to spot those signs and refer the students to treatment.
Treatment for mentally ill people is but one of the myriad issues before Congress, and it lacks not only headline-grabbing elements like semiautomatic weapons and gun-show loopholes, but also a backer like Mayor Michael R. Bloomberg of New York who can bankroll a multimillion-dollar advertising campaign to keep reminding voters to contact their senators.
Nevertheless, the issue has moved rapidly through the Senate, because of the efforts of the mental health lobby and because many legislators have a personal connection to mental illness. Senator Harry Reid, the majority leader, spoke the other day about his father’s suicide by gun.
Senate Democratic aides said that there is likely to be at least one mental health bill offered as an amendment to the larger gun package. The problem will be accommodating all of the additions.
Democrats have to agree to allow Republicans the same number of amendments as they give themselves. To reduce the likelihood that Republicans will offer multiple amendments that could water down and even torpedo the gun bill, it is in Democrats’ interest to limit their amendments.
A major reason proponents of this legislation see it as so significant is that unlike background checks or weapons bans, properly treating mental illness can prevent problems before a potential killer ever tries to buy a gun.
“Interestingly enough, if you look at Aurora, Tucson, Newtown, the people we’re talking about are very likely not individuals whose names would be on any lists,” said Ronald S. Honberg, the legal director for the National Alliance on Mental Illness. He noted that none of the recent spree killers he mentioned had been declared “mentally defective” by a judge, which is the legal standard for an individual’s name landing in the background check system.
Though more-stringent reporting standards into the nation’s background check system will undoubtedly help, he added, there will always be holes.
“It’s very difficult to come up with a system that’s foolproof,” he said. “The bigger point is if you really want to improve mental health care in this country, then let’s improve mental health care.”