Good psychiatrists don't seek to prescribe drugs to their patients, but if talk therapy hasn't worked, then drugs are the only solution left. Your argument is that the drugs are making them do it? They're not mentally ill? Wouldn't a smarter solution be not to give guns to mentally deranged people? The alternative you're suggesting is not to give psychiatric drugs to mentally deranged people, which makes no sense. Give them guns, but not pills that do help millions of other people, without incident.
The point is that mental illness and guns should not mix, and I don't see psychiatrists, patients, or most nra members saying they should. The only people who subscribe to the opposite of that belief, and who would like to continue to see deranged people be afforded the same rights as stable, law abiding gun owners is the head of the nra, gun sellers, and gun manufacturers. Getting rid of the right to own guns, or getting rid of all psychiatric medication are equally stupid suggestions, but so is allowing and advocating for mentally deranged people to be able to own guns.
Your thread proves my point: deranged people, with gun access, sometimes commit mass shootings, knifings. The fact that they're on medication is as irrelevant as saying they play Call of Duty or Mortal Kombat. Lots of people are on medication, play Call of Duty, Mortal Kombat, and don't commit mass killings. The most harmful link is that they're deranged and have guns, not that they're deranged and play video games, or they're deranged and are on meds. Even if they knifed people, and didn't shoot them, statistically your odds of surviving/evading that kind of attack would be better than surviving/evading a gunman. And, it would be easier for police to take down a deranged "knifeman" than a gunman. So, don't bring up the "hey, should we stop them from owning knives, too?" No. There's a reason you don't bring a knife to a gunfight.