It looks like Mischa Barton is on the mend.

The troubled actress appeared to be in good spirits last night at the Arizona Beverages All Points West party at Carrera Summer Escape in New York City's Cooper Square Hotel. "I'm really happy," she told Life & Style. "I'm feeling great."

Mischa, who was previously hospitalized at Los Angeles' Cedars-Sinai Medical Center last month, is in town to shoot her new TV series, The Beautiful Life. "Filming is going really well," she said.

The former star of The O.C. arrived at the party around 8:15 p.m., wearing a black skintight dress with cutouts on the sleeves and back. Accompanied by two girlfriends, Mischa danced wildly for 15 minutes. A few times she was seen outside smoking a cigarette.

As one eyewitness observed, Mischa's overall mood was lighthearted and laid-back. She drank only bottled water given to her as she danced. By 10:30, Mischa and her friends got into the elevator and left the party.

Photo Credit: Startraks