In the clip, Susan was asked if he ever showed any signs that he didn't want to live anymore. She responded, "No. Not even — no. No. I mean, he was sick and tired of what was going on, absolutely… and when he got the Parkinson's diagnosis, you know, I mean, in one sense, it was like: This is it. This is what we've been — we've been chasing something, now we found it. And we felt the sense of release and relief. But also, like, ‘Oh, my God, what does this mean?'"
As to whether she has any regrets, she said, "I know we did everything we could… People have in passing will come… They would say to me, 'God, I wish I had done something more for him. If only I had called him.' And I'm thinking, 'No one could have done anything more for Robin.' I just want everyone to know that. Nobody — no one — everyone did the very best they could. This disease is like a sea monster with 50 tentacles of symptoms that show when they want. It's chemical warfare in the brain. And we can't find it until someone dies definitively. There is no cure."
Susan's interview with Amy airs on Tuesday on "Good Morning America."