There are actually a lot of close psychological connections between isolated mass shootings from disillusioned angry young men and attacks associated with Islamic terrorism. Like most problems there are not any simple solutions.
Gun control is just one component. It does not address the fundamental reasons that this happens. You can make the argument that limiting the guns they use will help reduce the body count, and I do not entirely disagree with that. But the question occurs as to how many guns you remove from the hands of hunters and sportsmen, and how many guns you take out if the hands of law abiding folks.
The fundamental problem is the abundance of people, primarily young men, who not only feel they have nothing to live for, but are programmed to blame others for their misery. The lack of jobs, lack of romantic, sexual, cultural of educational outlets, and lack of family and community creates a lot of candidates for this abhorrent behavior. And it gets strengthened by the Internet which have sites that glorifies and encourages this way of thinking.
There are a lot of candidates to be radicalized in the Middle East, and it happens a lot. The life of a young man is terrible in a country in which all of the wealth, power and enjoyment of life goes to a very few families involved with oil, and the education and social interaction opportunities with members of the opposite sex are limited. The religious sheik tells them the Western World is to blame for their unhappiness and you get jihad. Unfortunately, much of the same happens in impoverished Muslim neighborhoods outside of the Middle East. Throw in the Internet as a marketing tool and you have the hell that exists today.
The life of a few disillusioned mentally-ill American male loners is not that much different than those recruited into Islamic fundamentalism. He does not believe that 72 virgins will be awaiting him in paradise, but the other mental illness is there. He has a shit life, thinks everyone else has it great, blames his misery on the rest of society, wants to die and wants to a lot of people out with him.
Most everyone on this board can list dozens of things they have that they enjoy in life and that they are looking forward to in the future. The mass shooters and jihadists are so different from sane people that it is hard to even begin to understand their way of thinking.
I think it happens in the U.S. more than in other countries because the differences in wealth and the economic and social divisions are so large. Sure Canadians have less access to guns, but I also believe there are fewer disillusioned young men in Canada that are cut off from civilization and rational thought. On the other hand, it is harder to accumulate significant wealth in Canada than it is in the U.S. largely as a result of Canada not leaving as many people behind. And I am not convinced that the wealthiest in the U.S. are willing to expend resources to minimize the number of potential gunmen. So I think the problem is more than guns, and that it is here to stay, unfortunately .