If you’ve ever loved someone who has been affected by mental illness, and maybe even if you haven’t, interview Katie Couric did today with Robert De Niro, Bradley Cooper, and the director of Silver Linings Playbook, David O. Russell was touching.

Russell sums up elegantly and affectingly why he wanted to make this movie for his son, who has a mood disorder. He talks about what it’s like to have a child whose moods could “pull him down the drain or turn into a tornado” on a moment’s notice, a son “who told me when he was 10 or 11 that life was so hard for him he didn’t know if he wanted to keep going.”

Russell says he wanted to make a movie that would help his son “feel like he’s part of the world.” And De Niro, asked what it meant to him to be involved in this very personal project, breaks down in tears, able to say very little except that he knows “exactly” what Russell is talking about.

The sweetest part of the interview is a discussion of the scene in the middle of the night when Pat, the bipolar character played by Cooper, has a meltdown. There’s a lot of yelling and screaming and crashing, and a nosy neighbor with a video camera shows up at the front door to see what the ruckus is. De Niro, Pat’s father, chases the boy away, in a protective fury.

That boy is played by Russell’s son. And Russell wants you to know that scene comes from his own experience. “You have this chaos in your house that’s so humbling. These reckonings of the soul, whether it’s a marriage or a child, they always seem to happen in your pajamas at 2 am, and you look over at your neighbors and say, it’s going down.”

Russell adds, “It was beautiful for my son to be the ‘other guy’ in that moment”—not the one melting down—as well as to find himself, momentarily, in Raging Bull. We would add that it was generous and lovely for this accomplished man to share his experience, and to recognize how many families fight every day to care for and protect struggling children.