Michael J. Fox has said he's now finding acting increasingly 'tough', as his Parkinson's disease has affected his short term memory so much that he can't remember lines anymore.
Fox, who was diagnosed with the degenerative disorder of the central nervous system back in 1991, first went public with his condition in 1998, but was able to continue acting.
However, the Back to the Future star has now admitted it's likely he'll no longer act as he struggles with his memory.
In a new interview with People, Fox said: "My short-term memory is shot.
"I always had a real proficiency for lines and memorisation.
"And I had some extreme situations where the last couple of jobs I did were actually really word-heavy parts. I struggled during both of them."
While he's been trying to improve his speech by practicing tricky tongue twisters, Fox said he's now decided to focus on writing.
He continued: "I'm down to this. My guitar playing is no good. My sketching is no good anymore, my dancing never was good, and acting is getting tougher to do.
"So it's down to writing. Luckily, I really enjoy it."
Fox has now penned a new book that details his journey with his illness, along with other themes like ageing and how we approach mortality.
The memoir, No Time Like the Future: An Optimist Considers Mortality, is released on 17 November, billing itself as 'a moving account of resilience, hope, fear and mortality, and how these things resonate in our lives'.
A synopsis says: "Michael shares personal stories and observations about illness and health, ageing, the strength of family and friends, and how our perceptions about time affect the way we approach mortality.
"Thoughtful and moving, but with Fox's trademark sense of humour, his book provides a vehicle for reflection about our lives, our loves, and our losses."
In the book, Fox also discusses the complications that came after he was diagnosed with a non-cancerous tumour on his spine.
Having undergone surgery, it took him four months to learn to walk again - only for a nasty fall in his kitchen to set him back again.
The book's synopsis adds: "Running through the narrative is the drama of the medical madness Fox recently experienced, which include not only his daily negotiations with the Parkinson's disease, but a spinal cord issue that necessitated immediate surgery.
"His challenge to learn how to walk again, only to suffer a devastating fall, nearly caused him to ditch his trademark optimism and 'get out of the lemonade business altogether'."Featured Image Credit: PA