I thought this article was very interesting.

The summary is that a few states have laws allowing people to put themselves on a list that forbids them from buying a gun. The idea is that people with things like bipolar disorder or severe depression may sign up so that they will not be able to buy a gun to commit suicide with during an episode.

While the first state to pass it was Washington, similar laws have since been passed in Virginia and Utah (which has some of the least restrictive gun laws in the country).

The state senator who introduced it in Washington stresses the difference from red flag laws, emphasizing that this is not an attempt at any kind of restriction, but rather at providing a tool to help people manage their mental health.