Dame Judi Dench "bravely" put her daughter Finty Williams into rehab in 2001.
Finty, 46 - who is the only daughter of Dench and the late Michael Williams - admitted that she turned to alcohol to help her deal with her father's death and her mother got her admitted to a rehab unit two week later when she saw that she was struggling to cope
Speaking on Dr Christian Jessen's podcast 'Second Opinion' - which covers a variety of medical subjects including addiction, mental health, and general well-being - she said: "After my father died in 2001 it just all went horribly wrong. My mother very bravely put me into rehab two weeks after my father died."
Actress Finty also revealed that her addiction to alcohol started when she was an insecure student at the Central School of Speech and Drama.
She explained: "I was 18 and had an inverted light bulb moment where I thought that nothing I could do or say or how I looked was ever going to be good enough.
"I was surrounded by very beautiful people -- they still are very beautiful people. At that point, I thought: 'If they're really drunk, then they won't notice that I'm really, really boring and short and round -- and don't look like a dancer and all of those things. These are extraordinary people who are all really talented and really funny and really clever and I don't belong here. And I'm none of the above.'
"The way I got through thinking that I was very boring and very unsparkly was by being the first person in the bar and being the person that bought the drinks for everyone."
Although Judi, 84, and Finty are incredibly close, Finty previously admitted it "pi***s her off" when people put her down as "not as good as" her Hollywood icon mum.
She said: "A lot of people want to go, 'She's not as good as her mother,' which is true, but I can also name you another 80 people who probably aren't as good.
"It pi***s me off, being pre-judged. That pi***s me off, pi***s me off hugely. Just because I don't think it's fair.
"I don't know whether, if your father is a brain surgeon, people go, 'He's not as good a brain surgeon as his father.'
"I don't know whether that happens, but because of who Ma is, a lot of people have an opinion, which they form before they get to know me or before they see what I can do."