Published Wednesday, 07 October 2009
The 35-year-old singer told GQ magazine about his previous addiction to prescription medication, including sleeping pills and painkillers.
"There was a lot of awful stuff going on," he told the magazine.
"I found myself in the same place that I've found myself in periodically since I was 17."
Asked what would have happened if he had not gone into rehab, Robbie said: "I would have died... A heart attack, I think... The left arm was going numb, chest was contracting. That's the sign, isn't it, that you're on your way out?"
Robbie was admitted to a clinic in Arizona in 2007, on his 33rd birthday.
He said he has been "really good" recently.
Asked about the possibility of rejoining Take That, he said: "It will happen. But not in the next 18 months, two years. There's contracts to fulfil. And then I can do what I want."
He said he did not feel bitter or jealous at Take That's success, saying he felt angry after quitting the band "because regardless of what I felt at the end... I loved them and I didn't think I was loved back".