Patti Davis shares advice for Bruce Willis's family as they travel 'heartbreaking road'

Patti Davis has shared her advice for Bruce Willis's family amid his dementia diagnosis.

Last week, the Die Hard actor's wife Emma Heming and ex-wife Demi Moore issued a joint statement in which they revealed that the 67-year-old was recently diagnosed with frontotemporal dementia (FTD) after previously suffering from aphasia.

Following the news, Patti penned an opinion piece for The New York Times in which she offered her support to the entire Willis family and reflected on how her father, former U.S. president Ronald Reagan, chose to make his Alzheimer's disease diagnosis public in 1994.

"I wasn't surprised - of course he would want the country to know. His love and loyalty to America ran deep," she wrote of finding out about her dad's decision. "And I shared my mother's pride in him for being so honest. She said he had just sat down, taken pen and paper and begun writing."

Patti went on to express her concern for Bruce and his family, noting the differences between her father's disease and the actor's.

"Bruce Willis and his family may have a harder road to travel than my family did," the 70-year-old continued. "Frontotemporal dementia is radically different from Alzheimer's. People with the condition can become unrecognisable in their outbursts, their aggressive and voracious behaviour."

Elsewhere in the piece, Patti insisted many people will "feel a little less lonely" after learning about Bruce's diagnosis.

"My hope for Bruce Willis's family, as they go down this unpredictable and heartbreaking road, is for those around them to know that simply being there is often all you can do. There is no sidestepping the grief, the pain, the helplessness. There is just, maybe, a human wall of comfort to lean on," she added.

Ronald died at the age of 93 in 2004.