The O.C. Cast: Then & NowSee how Mischa Barton, Adam Brody, Rachel Bilson and more have changed since their days in Newport Beach


Then: The girl next door wore Chanel on The O.C., where Barton played SoCal sweetheart-meets-damsel in distress Marissa Cooper until her character's tragic death in season 3.
Now: When It girl Barton left The O.C., her career took a backseat to her partying ways, leading to a 2007 DUI arrest and a 2009 suicide threat. "It was a full-on breakdown," she tells this week's PEOPLE. Today, she's staying positive and focusing on her upcoming roles in the supernatural thriller I Will Follow You Into the Dark and TV pilot Gutsy Frog.