Afterwards, Mc Adams starred opposite Cillian Murphy in Wes Craven's psychological thriller Red Eye, where she played a young hotel manager who is held captive by Murphy's character while aboard a red-eye flight.
She later parted ways with her publicist at the time, who had not informed her in advance.
"There were a lot of cooks in the kitchen, a lot of voices around me, and I wanted to step away so I could hear my own voice again", Mc Adams said in 2013.
"Truthfully, I never really wanted to be a big movie star.
I never even wanted to work outside of Canada, or outside of the theatre." Mc Adams returned to her film career in 2008.
Mc Adams' break-out role came in 2004, when she starred in the comedy film Mean Girls opposite Lindsay Lohan, Lacey Chabert and Amanda Seyfried, based on Rosalind Wiseman's book Queen Bees and Wannabes.
Mc Adams was 25 years old when she was cast as the mean high school queen bee Regina George, and she modelled her character on Alec Baldwin's performance in the drama Glengarry Glen Ross (1992).
In 2005, she starred in the romantic comedy Wedding Crashers, the psychological thriller Red Eye, and the comedy-drama The Family Stone.
She was hailed by the media as Hollywood's new "it girl", and received a BAFTA nomination for Best Rising Star.
Tina Fey, who co‑starred in the film and wrote the screenplay, has credited Mc Adams with teaching her how to act in front of a camera rather than an audience: "She's a film actor. And so I kind of learned that lesson from watching her." Later in 2004, Mc Adams starred opposite fellow Canadian Ryan Gosling in the romantic drama The Notebook, based on Nicholas Sparks' novel of the same name.