When there's a horrific mass shooting, there's a bit of discussion about the role of mental illness. Religion and culture are blamed for some of these events, and mental illness is suggested as a likely culprit in others. Leaving aside the fact that we grant that it's somehow not the fault of some people who commit these atrocities - just bad chemicals in the brain - and it is the fault of others and their religion, there's always a bit of another backlash to the desire to attribute some of these events to the mental illness of the perpetrators. Correctly, people point out that there isn't isn't a link between diagnosed mental illness and this kind of violence.
I'm no expert and have no desire to play one on TV on this subject, but whatever we call it, there seems to be something deeply wrong with anyone who would go kill 50 strangers. That doesn't mean that everyone who is diagnosed with depression or bipolar disorder is likely to - or more likely to - commit violent acts, just that I'm not sure how to see these people as anything other than mentally off kilter? You gotta be broken to do this type of thing.