Does anyone know how to "explain" this disorder to these men? Is there a website they can refer to?

I think I'm confused about what you mean by "closure." What you're describing sounds more like feeling like you aren't responsible for what happens to him anymore? Something like that? Or am I off base? I think what you mean is that you don't want to feel guilty about leaving him. The thing is you are both adults and you aren't responsible for him anyway. It's up to HIM to deal with his disorder and talk to his therapist about it. I think he's just blowing smoke with you when he says he's interested in the diagnosis, but wants YOU to help him out with it, get info on it, etc. He's trying to make YOU be responsible for him. But he's not two years old, he's an adult. You are responsible for you, and for your kids, and he is responsible for himself (and for his kids, but they suck at that). This is not just true of him, it's an important reality of life. Too many "savers" on this site... we are each responsible for our own lives and choices. No one can do it for us, and no one can do it for them. I can't imagine what the course of your marriage has been like when you feel you have to make so many excuses for him being an idiot and have to find some way to teach him something about himself, that he cannot even handle googling something by himself. My kids are in elementary school and can do that. If he's a gigantic child, that's not your problem. That's HIS problem. "Closure" is about knowing in your heart that the relationship is over and there is nothing you can do to change him. That is something they will never give you. You have to reach that point yourself. Giving him an internet article is not going to help you with that. And if you did give him something, it would just be something that he would then use to argue with you about, to blame you for, make you feel guilty for, project that it's you... whatever. There is no interaction that is helpful or "works" with them. I think the time would be better spent on YOU researching and understanding the disorder, so that you can really own the knowledge that the only way to deal with a narcissistic personality is NOT to deal with it. Extricate yourself. It's not your fault. You didn't cause it and you can't fix it.