Nigella Lawson will return to court today to finish giving evidence in the trial of two of her former personal assistants.
Yesterday TV cook Ms Lawson admitted to using cocaine and spoke of the "intimate terrorism" she suffered at the hands of Mr Saatchi.
Italian sisters Francesca Grillo, 35, and her sister Elisabetta, sometimes referred to as Lisa, 41, are accused of committing fraud by abusing their positions by using a company credit card for personal gain.
Jurors were previously read an email sent to Ms Lawson from her ex-husband Charles Saatchi in which he said the Grillo sisters would "get off" on the basis that she was so off her head on drugs she allowed them to "spend whatever they liked".
She said she took the class A drug with her late husband John Diamond when he found out he had terminal cancer, and on another occasion during her troubled marriage to Mr Saatchi.
But the 53-year-old, who also admitted to smoking cannabis, said the idea that she is a "drug addict or habitual user of cocaine is absolutely ridiculous".
Standing in the witness box at Isleworth Crown Court in west London, Ms Lawson admitted taking cocaine on six occasions with her late husband Mr Diamond.
"It gave him some escape," she told the court. "There was another time I took cocaine.
"In July 2010 I was having a very, very difficult time. I felt subjected to intimate terrorism by Mr Saatchi."
Ms Lawson told the court the experience "completely spooked" her.
"The idea that I am a drug addict or habitual user of cocaine is absolutely ridiculous," she added.
The Grillo sisters, of Kensington Gardens Square, Bayswater, west London, deny the charge against them.
Prosecutors claim the Grillos lived the ''high life'', spending money on designer clothes and handbags from Louis Vuitton, Christian Dior and Vivienne Westwood.
The pair are accused of using credit cards loaned to them by the TV cook and her ex-husband Mr Saatchi to spend more than £685,000 on themselves between 2008 and 2012, the jury has heard.