Mischa Barton should have been flashing a bright smile as she soaked in the sun at the pool at the Four Seasons hotel in Beverly Hills on July 14. Her new movie, Homecoming, was about to premiere, and she was a week away from starting her starring role on the new CW series The Beautiful Life. But instead she seemed sad. "She looked tired and distraught," says an eyewitness. "Something was definitely wrong with her."

Clearly, something was very wrong. The next day, Mischa was "removed from her home," according to LAPD officer April Harding, and placed under involuntary psychiatric hold at Cedars-Sinai Medical Center in Los Angeles. "She went on a three-day drug-and-alcohol binge," claims an insider close to the troubled 23-year-old star. "She'd been up for three days and started having hallucinations. She was screaming that she had ants and spiders crawling on her."

For more on Mischa's troubles, pick up this week's issue of Life & Style, on newsstands now!

Photo Credit: Retna