Interesting, but not helpful, IMO (unless I missed something).
OK, so maybe psychotics are statistically overall not much more inclined to violence than the average person (I would have preferred numbers to 'fractionally', and 'substantially'). And maybe those with addictions are more likely to commit violent acts. Those [-]numbers[/-] inferences, IMO are distractions.
I'd imagine the addicted create violence in the act of stealing money to feed their addiction. It is a means to an end. Often completely unnecessary to get the money, but they are in this position with a gun, not thinking clearly, and they pull the trigger even if they could get out w/o pulling the trigger. But with assassinations, the violence is the end itself.
This is despite the fact that your chance of being murdered by a stranger with schizophrenia is so vanishingly small that a recent study of four Western countries put the figure at one in 14.3 million. To put it in perspective, statistics show you are about three times more likely to be killed by a lightning strike.
There is no point to that. Assassinations are also extremely rare events. So any trend in their causes would also be extremely rare. A better way to look at is, of the people who were killed by lightening, what was the cause?
NWS Lightning Safety Fatalities
We might as well say that no one should ever be under a tree, because that is where most lightening fatalities occur. Or we might say there is little risk at being under a tree in a lightening storm, because your chances overall of being killed by lightening are only ~10 in 300,000,000.
So more to the point I believe, is of assassinations/attempts, how many are caused by psychotics? Just off the top of my head, Reagan (Hinckley), Gerald Ford (Squeaky Fromme), John Lennon (Chapman - I guess this is 'murder' not assassination, but it fits as violence as the end goal, and Lennon was a political activist in a way). Others have political ties (Lincoln-Booth, etc), but the % of psychotics seems high to me.
IMO, the author of that article either does not understand that, or has an agenda.
-ERD50