Arquette has "completed treatment and has left rehab," his rep told E! News.
2010 was a rough and tumble year for the 39-year-old Scream star. He separated from his wife of 10 years, Courteney Cox, publically spoke of his sleeping with other women (among other things) to Howard Stern, and continued partying right up until entering rehab on Jan. 1.
"He was an absolute mess, clearly drunk and was partying with little people dressed like Oompah Loompahs," a source from inside the party revealed.
Courtney has stood by her estranged husband, telling E! News, " I really admire David and his choice to take charge and better his life. I love and support him."
As for Arquette's future plans, business partner Jeff Beacher told E! News that the actor will no longer be working with Beacher's Madhouse, the show the duo started together.
"He's concentrating on his health right now," Beacher said.
—Additional reporting by Ashley Fultz