Pharmaceuticals?
“.........According to the Citizens Commission on Human Rights International, “At least 36 school shootings and/or school-related acts of violence have been committed by those taking or withdrawing from psychiatric drugs resulting in 172 wounded and 80 killed (in other school shootings, information about their drug use was never made public—neither confirming or refuting if they were under the influence of prescribed drugs).”
Valium is hardly the drug that sets off murderers, lol. Coke, on the other hand...
There’s also the theory that some antidepressants induce extreme violence precisely by doing exactly what they’re supposed to: make people feel calm & confident in doing what they are inclined to do - and if that’s murder a bunch of people, then they’ll feel good about going about doing it.