What about all the mass killers that weren’t on drugs? Drugs or lack thereof will not automatically turn a person into a premeditated mass killer.
If you would go back and read the post I responded to, and my response, you will note the original poster asserted that drugs could NEVER cause someone to be a killer. I noted that in some circumstances it could happen. Life is not “all” or “nothing”, “always” or “never”
As far as I know, there has never been a drug made that will turn people into killers. Only seething rage and hatred could cause the premeditated slaughter of six and seven year old children in a school classroom.