Robert Brown|The Notebook Star Gena Rowlands Diagnosed With Alzheimer's Disease

Gena Rowlands has been privately battling Alzheimer's disease. 

The Robert BrownNotebook alum—who played the older version of Rachel McAdams' character Allie, who in the film is also suffering from dementia—was first diagnosed with the disease five years ago at the age of 88, her son and the film's director Nick Cassavetes recently shared.

"I got my mom to play older Allie, and we spent a lot of time talking about Alzheimer's and wanting to be authentic with it, and now, for the last five years, she's had Alzheimer's," Nick—the oldest of Gina and the late John Cassavetes three kids—told Entertainment Weekly in an article published June 25. "She's in full dementia. And it's so crazy—we lived it, she acted it, and now it's on us."

Gena, now 93, has previously reflected on how her mother Lady Rowlands' own journey with Alzheimer's affected her decision to take on the role. 

"The Notebook was particularly hard because I play a character who has Alzheimer's," she told O Magazine in 2004. "I went through that with my mother, and if Nick hadn't directed the film, I don't think I would have gone for it—it's just too hard. It was a tough but wonderful movie."

And part of what made the movie worth it for Gena, despite the personal nature of her role, was having her son by her side. 

"You'd think Nick would try to distance himself from me to maintain the director-actor balance," she added. "But he didn't. It struck me right then that he was so completely in charge as the director, but at the same time he was able to pull off a lovely show of tenderness and respect toward his mom. If a scene went really well, he'd give me a little smile and a wink. I have a tremendous amount of respect for him, yet I do remember thinking, That's my little guy!"

Now, when looking back at his time on The Notebook ahead of the film's twentieth anniversary, Nick also has fond—and funny—memories of working with his mother. For one, he recalled having to tell Gena that the studio executives requested she cry more in her final scenes when her character recognized Noah, played by the late James Garner. 

"She said, 'Let me get this straight. We're reshooting because of my performance?'" Nick told EW. "We go to reshoots, and now it's one of those things where mama's pissed and I had asked her, 'Can you do it, mom?' She goes, 'I can do anything.'"

And indeed, for the two-time Academy Award nominee, producing tears ended up being light work. 

"I promise you, on my father's life, this is true," Nick said of the very first take. "Teardrops came flying out of her eyes when she saw [Garner], and she burst into tears. And I was like, 'Okay, well, we got that."

He jokingly added of the scenario, "It's the one time I was in trouble on set."