ichard Madeley's mother "ceased" to know him as her son while she was battling dementia.
The 63-year-old TV presenter has recalled how the devastating disease - which causes a decline in memory and makes it difficult to complete everyday activities - took the life of his late mum, Mary Claire, aged 83, after she was diagnosed with dementia and incurable lung cancer on the same day.
He told the Daily Express newspaper: "All of us were agreed on one thing from that moment. We hoped the tumour would get her first.
"In fact that's what my mother told me on the phone that night, "I want to die as me," she said simply.
"Mum lived for another two years. By then, she had ceased to know me as her son and called me Bailey, her brother's name. "You're my kid brother, aren't you?", she'd say whenever I visited her, as often as I could considering she lived in Norfolk and I in London."
Richard also recalled when his mum thought Christmas was in July, but thanks to daily visits from a carer, Mary was "fundamentally functional".
She added: "She phoned me one hot July evening to ask, "Is it Christmas this weekend? Are you coming?" But with daily visits by the carer she was fundamentally functional.
"If I was taking her to lunch, I'd call to remind her in the morning and when I arrived, she'd be sitting in the kitchen with her hat, and coat, make-up applied, hair neatly brushed.
"But the house lights were always off, even on the darkest days. She'd be sitting there in the shadows, like a ghost."
The TV host - who has kids Jack, 33 and Chloe, 31, with his wife Judy Finnigan - is hopeful that continued research and funding into the cruel condition will "eventually" make it a "survivable illness".
He said: "I think we are moving towards the same place where we now stand with HIV - a multi-targeted approach that will eventually make dementia a liveable, survivable illness."