Arquette's personal life began making headlines late last year after his 11-year marriage to actress Courteney Cox broke down. The separated couple have a young daughter named Coco.
"He's trying to win Courteney back, and he turned back to drinking again out of frustration," a source told UsMagazine.com Monday. "He is doing this to show her he means it and will do anything for her and Coco. He wants his family life back. It's been so hard on him."
Exactly when Arquette went into rehab or where he is being treated were not reported.