E! News reached out to Mischa Barton for an interview, where she talked about her time on the show and why she left.
Checking In on The O.C. Cast After Mischa Barton's Bombshell Revelations
https://t.co/FFBCMVWBb6- E! News (@enews)
May 20, 2021 E! News asked when conversations started about her leaving the cast, and she said:
"It's a bit complicated. It started pretty early on because it had a lot to do with them adding Rachel [Bilson] in last minute as, after the first season, a series regular and evening out everybody's pay-and sort of general bullying from some of the men on set that kind of felt really s--tty. But, you know, I also loved the show and had to build up my own walls and ways of getting around dealing with that and the fame that was thrust specifically at me. Just dealing with like the amount of invasion I was having in my personal life, I just felt very unprotected, I guess is the best way to put it."
She also said that they started doubling up on episodes and shooting became a lot harder. She said she was getting offers from big films at the time, but had to turn them down. More at the source.
Source