"When I had my first drink of beer, I must have been four-years-old," he told Oprah. "I was down in the basement with my dad and beer was there and I just grabbed it and drank it. And I remember that. It's one of my earliest memories."
The 39-year-old actor said that he "started seriously drinking probably when I was about 12" and admitted to stealing pot from his dad when he was 8.
He also said that Cox and his sister, actress Patricia Arquette, urged him to enter rehab in January.
"I came back from Miami and I had taken a nap. I woke up and Patricia and Courtney were at my bed," he recalled. "Courtney had a cup of coffee. I was like, 'What are you two doing here together?' I already knew."
He said upon waking up and going into the living room, he was also confronted by his best friend, his business partner and a third man he didn't know.
"I go 'What up,Turkeys? I guess this is my intervention!'" he said.
Arquette's apperance is a fill in for Philadelphia Eagles quarterback Michael Vick, who recently backed out of a scheduled sit down with the talk show queen.