It's the same with me. I have a friend for four years now; and after all of this time, he still does not get it. I explained it to him the best I can. He tries to understand, but comes up short. Funny thing is that his sister suffers from depression. And I think she's had it for most of her life.

There had been times, when I talk to him about it, he would just suddenly change the subject.

I don't have an answer for you. If I like someone, I would try to understand and research any kind of problem they have.