Seriously, we do believe these shooting are correlated with just plain mental illness. Which are largely "treated" with "those hardcore FDA drugs" (which SSRIs, due to the low side effect profile, really aren't), so therefore I'm not surprised there seems to be a correlation between the two. However, after a fair degree of study, and discussion with one of my psychiatrists a dozen or so year ago, I don't think there's causation, just correlation. Or at least he didn't believe the "antidepressants give you enough energy to be violent" thesis based on all three generations of them.
I can say that sadly I'm one of those people that don't do well on SSRIs (at least the withdraw from them). I literally wanted to stab my own mother and sister when I was coming off of SSRIs (Zoloft). I literally felt so angry at everyone and everything. So, I'll never go on SSRIs ever again.
If you believe the self-provided warnings for these drugs, most or all of them warn about suicidal/violent mood side effects.
One thing that people may not have heard about the Columbine shooters (because of the usual press corruption) is that they were sexually abused by the police, and were trying to get back at them.
Well, the same applies to the gun used (no causation, only correlation) and yet people and the media keep bringing guns up as if the correlation between 'using guns'<->'shooter kids' is stronger than 'using SSRIs'<->'shooter kids'.
The psychiatrist you mentioned surely believes the same of guns, that guns can't possibly "give you enough energy to be violent". Because mostly they don't.
You and I would be interested in seeing that data, and you and I will never see that data. ;)
Also the media never ever mentions most of those shooter kids were on those hardcore FDA drugs.
What's the point? We know the gun was responsible for the killings. /s