Mischa Barton was taken to hospital after police were called to her home on Thursday morning. Officers responded to various calls at around 7:15am from neighbours, who reported a disturbance coming from Mischa's West Hollywood apartment.
People reports that Mischa was at home with one other house guest. According to Sergeant Duncan of West Hollywood Sheriff's Department, the actress was "fully clothed" and "speaking in coherent statements" when the police arrived. She was willingly taken to hospital.
TMZ, who first reported the news, claims that the former star of The O.C. was transported for a mental evaluation.
Mischa Barton was taken to hospital on Thursday morning
The British-born actress suffered a mental breakdown in 2009. At the time, she was taken to hospital in an episode she described as "straight out of Girl, Interrupted".
Mischa was committed to a psychiatric ward for four days under California's 5150 hold, a section that authorises a qualified officer or clinician to involuntarily confine a person suspected of having a mental disorder that makes them a danger to themselves and others.
At the time, Mischa, who turned 31 this week, told People: "It was a full-on breakdown. It was terrifying. Straight out of Girl, Interrupted. Story of my life."
She is best known for playing Marissa Cooper on The O.C.
Mischa was born and grew up in London but moved to the US as a young girl. The child star broke into acting and won roles in Notting Hill and The Sixth Sense.
Mischa has had a turbulent relationship with her mother Nuala. In 2015 the actress sued her mum, alleging that she had stolen money throughout her career.
Legal documents filed in April showed that Mischa also accused her mother of bullying and not allowing her access to a Beverly Hills home that was purchased with money earned from her career as a child actress.
The lawsuit stated: "While Barton was busy perfecting her craft and turning her acting dreams into reality, her mother, defendant Nuala Barton, was secretly scheming to exploit Barton's burgeoning career for her benefit."