The son of legendary racing driver Sir Jackie Stewart has said it has been "awful" to see his mother become "no longer the person" he knew because of dementia.
As per BBC, Mark Stewart said his mother, Lady Stewart, was "constantly getting worse over time" because of the condition, which she has had for the past 12 years.
It comes as the family's charity, Race Against Dementia, launched a world-first clinical trial alongside the University of Oxford to help stop the condition from developing.
"One thing that we should have left is our memory, and our ability to recall our lives and the achievements and all the things that you've done together," Mark said.
He further stated, "These moments are erased, they're no longer in their minds and you're unable to discuss them anymore because that's dementia, and it's just awful."
Lady Stewart was diagnosed with dementia in 2014, with Sir Jackie previously telling the outlet that it had led to "horrendous" behaviour and language changes, including forgetting who he was.
"She's still been pretty cheerful at times but very aggressive at others, and it's no longer the person that was the matriarch of our family - it's no longer that individual," Mark explained.
Almost 10 years ago, the legendary, three-time Formula One Champion, Sir Jackie Stewart began the initiative Race Against Dementia to speed up progress towards a world without the disease.
"I love that out of the box thinking and that Formula 1 mindset - they're constantly looking at new ways of doing business," Mark, who is the chair of the charity's trustees, said.
"That mindset is so incredibly important to what Race Against Dementia does - we are not just looking for cures, but prevention,” Sir Jackies Stewart’s son, concluded.