It’s almost as if mental illness is a complex medical diagnosis that few HN commenters are qualified to make...

We're obviously thinking about this in light of the fact that she just went on an attempted killing spree. I can see how that might prejudice our thinking.

But I personally have had quite a bit of experience interacting with mentally-ill individuals both as a volunteer and through visiting family members who are in institutional care.

I am in no position to diagnose anyone, but I'd be very surprised if it does not come out that this woman had long-standing mental issues for which she refused any intervention or treatment.