Robert De Niro gets emotional during Katie Couric interview

Robert De Niro welled up with emotion before pausing and composing himself during an interview Monday with Katie Couric about his film "Silver Linings Playbook," in which he plays a father whose adult son suffers from bipolar disorder.

After director David O. Russell -- who appeared on "Katie" with the movie's stars De Niro and Bradley Cooper -- explained that his son has a mood disorder, Couric asked De Niro if he felt "a greater responsibility [than usual] doing a film that David has so much personally invested in?"

"Oh, of course, I mean I understand what he... " the two-time Oscar-winner began, and then stopped and began to tear up. After a moment he held his hands to his eyes as Cooper, who plays his son, put his arm on De Niro's shoulder. "I don't like to get emotional," De Niro said at last, "but I know exactly what he goes through."

Russell told Couric that when he first showed De Niro the screenplay, "This is what happened. And I thought he was having hay fever and I realized he was having an emotional reaction. I sat there and I watched Robert De Niro cry for 10 minutes and I said [to myself], 'Wow, he's really connecting with this material and this would be a beautiful thing if it could work out, because I think his heart would be there.' And it is there."

In an interview with the Los Angeles Times in November, De Niro, a father of six, alluded to having a child with difficulties.

"There's a helplessness because there's not much you can do about it," he said. "I don't want to say too much more and get personal. But it can be very upsetting."