Washington, July 21 : Actress Mischa Barton’s wild party lifestyle and reported drug and alcohol use over the past two years has cost her friendships with close pals, such as Nicole Richie, sources have revealed.

"In the last few years, her dark side has really come out," People magazine quoted a source close to both Richie and Barton as saying.

"Her friends, like Nicole, want to be supportive but they really can''t be around her too much. She''s too volatile.

"It makes us sad, but we''re also like, ''Pull it together and get help already,''" the source added.

The former O. C. star, who has been placed under psychiatric hold, has been dealing with personal issues, says another source.

A close friend of Barton also says that the actress "alienated herself from a lot of her friends." (ANI)