The 'American Reunion' actor - who checked himself into the Cirque Lodge rehab facility in Utah for a 30-day addiction program after his second drink-driving arrest in 2010 - says his booze problem was so bad that he feared for his life.
He told People magazine: "I would have died, and I think about that every single day.
"Today, I'm the luckiest guy alive."
Chris admits it was his meteoric rise to fame which set him on the downward spiral and although he embraced his fame at first, calling it "magic", it didn't take long for his addictions to take over.
He explained: "[At first] It was nothing short of magic. [But] It got to the point where I was a fragile shadow of the young man that came into this business."
Chris' March 2005 break-up with Katie Holmes- who he got engaged to in 2003 after three years of dating - coincided with first arrest for driving under the influence (DUI) in February 2005.
Chris split from Ginnifer Goodwin in 2008 and after his second arrest in 2010, his publicist explained that "after recent events, Chris was forced to take a clear look at a problem he has been trying to deal with himself for years. He understands now that he cannot beat this disease alone".