Demi Moore attends the LA premiere of "Corporate Animals" at NeueHouse on Wednesday, Sept. 18, 2019, in Los Angeles. Picture: AP

Demi Moore's daughter Tallulah Willis has described seeing her mother relapse as the sun going down and "a monster came", and the 25-year-old star admits she used to feel "anxiety" when she noticed the "Ghost" star was coming face-to-face with her demons again.

The 25-year-old star sat down with her sisters Rumer, 31, and Scout, 28, and her 56-year-old mum to speak about her mother's addiction issues, and she recalls feeling "anxiety" when she would begin to notice the "Ghost" star was relapsing.

Asked what was "scary and unsafe" for her in regards to her mother's relapse, Tallulah said: "It was like the sun went and down and like a monster came.

"I remember there's just the anxiety that would come up in my body when I could sense that her eyes were shutting a little bit more, the way she was speaking.

"Or she would be a lot more affectionate with me if she wasn't sober."

Rumer added: "It was jarring."

Tallulah admitted she would be "very upset" when Demi - who relapsed during her marriage to Ashton Kutcher after suffering a miscarriage aged 42 - was facing her demons, and she would have to treat her mother "like a child" during such times.

Speaking on Jada Pinkett Smith's "Red Table Talk" on Facebook Watch, she added: "It was very weird, and there were moments where it would get angry.

"I recall being very upset and kind of treating her like a child and speaking to her like a child.

"It was not the mom that we had grown up with."

Demi recently opened up about battling drug and alcohol addiction in her memoir 'Inside Out', as well as discussing being sexually assaulted and talking at length about her difficult childhood.

And Rumer has admitted she is "so proud" of her mum for showing such "vulnerability".

She said: "I'm so proud of her vulnerability, and I think so many women have watched her, and just as her daughters watch her, as this beacon of strength and this kind of leader.

"And I think, what I really respect about her is that she is never the victim in her stories.

"She takes accountability. She takes responsibility, and mind you, this is her perspective, her story, and she's the first one to say that.

"But she's allowing herself to show everyone that you can go through some really difficult, hard things, and you can still be someone who is thriving and taking accountability and just being a strong survivor."