Thank you so much for writing this. As a victim of narcissistic abuse, and a neuroscientist, I couldn't agree more. My guess is that for those who are incapable of empathy, and with anti-social personality, that their trauma comes often in the womb or might even be inherited. The brain structural differences could either be due to a lack of differentiation due to a localized loss of blood supply, nutrients, toxins or pathogens. But abuse doesn't create a lack of empathy. Abuse can make you emotionally disregulated, and that is very different!
People who've had severe abuse might exhibit sociopathic behavior due to an inability to regulate their emotions, but they would be capable of seeing the errors of their crime. Psychopathic narcissists are incapable of empathy, humility and seem to delight in the misery of others.
A psychopathic narcissist would be much more inclined to manipulate a therapist. They have no interest in changing.
The best way to deal with narcissistic psychopaths is to have laws in place designed to protect the rest of us. And to enforce those laws. The more narcissists are allowed to get away with their sociopathy, the worse it gets. We've seen what can happen when they are in power!