Fredrick Vars is a professor at the University of Alabama School of Law.

Two-and-a-half years ago, Cheryl Hanna had many reasons to be happy. She was 48, a successful Vermont law professor and married with two children. But Hanna was privately battling severe depression. In the days leading up to her suicide, she had twice voluntarily admitted herself to a hospital for psychiatric treatment. Shortly after her second hospitalization, she legally bought a handgun and used it the next day to kill herself.

People at risk for suicide, like Hanna, should have the option to make it more difficult for themselves to buy a gun during a suicidal crisis. What if we allowed people to put their own names into the existing federal background check system and thereby prevent themselves from buying a gun from a licensed dealer? The signup process — whether by mail or online — would be voluntary and confidential and require identity verification. People could have their names removed from the system by request, with a waiting period to ensure adequate deliberation.

This simple proposal could save lives. More than 20,000 gun suicides occur each year in the United States, hundreds committed with recently acquired weapons. One study found that the rate of firearm suicide was 57 times higher among recent handgun buyers than among the general population. Many suicides are impulsive, and most people who survive an attempt change their minds. With a gun, there is seldom a second chance. So it is not surprising that mandatory delays in buying a handgun are associated with lower suicide rates.

Many people at high risk would sign up for the proposal. For a paper e-published Oct. 5 in the journal Suicide and Life-Threatening Behavior, my co-authors Karen Cropsey, Cheryl McCullumsmith, Richard Shelton and I surveyed 200 inpatients and outpatients receiving psychiatric care at the University of Alabama at Birmingham. We reported that 46 percent of participants said they would be willing to put their names on a “no guns” list. Presumably, they would do so because they fear impulsive gun suicide. This suggests that perhaps millions of volunteers would register for the proposal and hundreds of lives could be saved each year.

We did not expect so many volunteers, particularly in Alabama, where gun rights are important to a high percentage of people, but in retrospect this should not have been surprising. People seeking treatment for mental illness understand that they are at high risk of suicide. Almost all would rather live than die. That so many would want to put firearms further out of reach is understandable and a powerful expression of their autonomy and will to live.

Significantly, this proposal has the potential to save lives at little cost. The federal background check system is already operating and funded. The only new permanent expense would be processing signups and removals. A simple federal statute could implement the proposal nationwide, but it could also work at the state level.

Because the proposal is voluntary and confidential, it would not raise any serious constitutional concerns. This is not gun control; it is self-control. The Second Amendment gives us a right to bear arms for self-defense. For some people, self-defense means keeping firearms at a safe distance.

Cheryl Hanna was one of those people. Her suicidal impulses were the motivation for her voluntary hospitalizations. She had sat in her car in the parking lot of gun shop a couple of weeks before her death, contemplating the very course of action she eventually couldn’t resist. When asked about this proposal, Hanna’s husband, Paul Henninge, said: “I think she would have signed up for this in the last two months of her life. I know she had her good days. And I think she would have done that.”

People who fear suicide should have this option. Help them help themselves.