Gena Rowlands, the Oscar nominated actress of films including A Woman Under the Influence and Another Woman, has Alzheimer’s disease.

In one of her most famous later roles, Rowlands played the older version of Allie, one of the two central characters in the popular romantic drama The Notebook. In the film, the older Allie suffers from dementia.

The Notebook was directed by Rowlands’ son, Nick Cassavetes, who revealed his mother’s diagnosis in a new interview with Entertainment Weekly about The Notebook’s 20th anniversary.

“I got my mom to play older Allie,” Cassavetes explained, “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 … she’s in full dementia. And it’s so crazy — we lived it, she acted it, and now it’s on us.”

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The Notebook tells the love story of Noah and Allie, played by Ryan Gosling and Rachel McAdams, the story is framed by scenes involving an older couple, played by James Garner and Rowlands. The story Garner has been telling Rowlands throughout the rest of the film is their own romance from the 1940s, which Allie can no longer remember because of her illness.

In real life, Rowlands’ mother, Lady Rowlands, also suffered from dementia. Rowlands had previously discussed how caring for her mother during her illness informed her performance in The Notebook.

Looking back on the movie 20 years later, Cassavetes told EW he thinks The Notebook “holds up pretty good … I’m just happy that it exists. It seems to have worked and I’m very proud of it.”