We put a lot of trust in professionals and people in leadership positions.
People have to perform mental physical psychological fitness tests for a number of things in our society less important than owning a gun. There are people people that get paid to sometimes make difficult assessments and decisions based on well thought out scientific criteria. I just think something has to be done about treating it as a medical issue. Having doctors sign off on whether someone exhibits enough mental capacity to own a gun in some way.
Not claiming that would fix everything, but it could help.