Mischa Barton on Starting a ‘New Chapter’ on ‘The Hills’ Reboot (Exclusive)

Barton is a new addition to the cast, along with Pamela Anderson and Tommy Lee's son Brandon.

Since rising to fame as Marisa Cooper on The O.C., Mischa Barton has ridden a rollercoaster of ups and down, including hospital stints, fashion ventures, break ups, legal drama, a mental breakdown and television projects. But as she prepares for the premiere of her latest gig -- MTV’s reboot of The Hills -- she’s ready to turn a new page.

“I do feel I’ve been through a lot, especially in the last few years,’ Barton told ET's Keltie Knight, reflecting on the last decade while promoting The Hills: New Beginnings. “It’s definitely starting a new chapter in my life.”

“I’m great,” she added about how she’s doing these days. “This has been an interesting journey and it’s been really fun to do. I’m really happy to be back in LA.”

Barton is one of two newbies joining original stars including Spencer Pratt and Audrina Patridge in the reality series, set in Los Angeles, California.

Pamela Anderson and Tommy Lee’s son, Brandon Thomas Lee, also joins the show, which premieres on MTV on 24 June.

Despite never appearing on the original series, Barton knew some of the cast members, so producers thought she would be a good addition for the gang.

She describes her role in the cast as the “voice of reason,” but hints she’ll still be involved in some drama, notably with her love life.

“I do have a boyfriend when the show starts, but you"ll see,” Barton teased.

As for Lee, he was only 10-years-old when the show premiered in 2006. And, having also gone through personal struggles, like alcoholism, in recent years, he was wary of getting involved with reality television.

Ultimately, it came down to timing, he told ET.

“If MTV would have asked me at any other time in my life, I would have absolutely said, ‘No,’” said Lee, noting his famous parents might make an appearance om the show.  “I've been sober for a really long time now. But now it feels like the perfect time for me.”

See more on The Hills: New Beginnings below.

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