The problem is not Mental illness! In the best-case gun control is a stupid attempt to address a symptom of the breakdown of society. The ills of society that we are seeing is due to that very society and addressing the symptoms cannot fix the ills. It is society that has gone amuck. It is society that needs fixing.
Look back 50+ years. Guns could be purchase if you had the money. You could live in a shack if that is what you could afford. There were definite expected roles for men and different expected roles for women. Boys were given a gun on becoming of age usually in their early teens. There were jobs even for people on the lower half of the IQ curve. A single wage earner was sufficient to raise a family though it was preferable not to be a hired hand.
So today, it is women and POC that get the jobs and the promotions. What is a young man to think when society is saying that he has no role? That he is not wanted? Yet, he can look at what is being achieved and be alarmed.
Does recognizing reality make him mental ill?