Diane Keaton Secretly Battled Dementia in Final Years, Family Confirms Pneumonia Cause of Death

Diane Keaton, who passed away on October 11, 2025, at age 79, was reported to have been secretly battling dementia for several years, according to sources from Showbiz 411 and NewsNation. Despite her family’s statement attributing her death to pneumonia, insiders revealed she struggled with memory loss and had difficulties remembering lines while filming the 2022 movie ‘Maybe I Do.’ She used an earpiece on set to cope, and co-star William H. Macy was supportive during these challenging moments. Keaton’s mother also had Alzheimer’s, and Diane was surrounded by family and caregivers during the last months at a discreet resort in Palm Springs. Friends noted her visible weight loss after she spent months in Palm Springs due to damages to her home caused by wildfires. Her family encourages donations in her memory to food banks or animal shelters, highlighting her love for animals and support for the unhoused community. While the family has not publicly confirmed her dementia, reports paint a picture of a private struggle away from the public eye.