[Lurking Libertarian]

Why are all mass shooters, past and present, always on some similar type of prescription drugs, most notably antidepressants?

On literally my first day in college, I learned about the fallacy of the "one-way correlation." It's doubtless true that 100% of mass murderers drank milk as children, but that means nothing unless you also know what percentage of milk-drinkers went on to become mass murderers.

[Dr. Sivana]

It's doubtless true that 100% of mass murderers drank milk as children, but that means nothing unless you also know what percentage of milk-drinkers went on to become mass murderers.

True. But on the flip side, if we know that 20% of a population subset is on anti-depressants, but 90% of events are caused by people on anti-depressants, that is meaningful, and at least invites further study.