'Sherlock Holmes' actor Robert Downey Jr admits the six years he has spent drug-free feel like a ''lifetime'', but that he can't pretend it didn't happen

The Hollywood legend - who has previously claimed to have not touched drugs since July 2003 - admits his battle with illegal substances and alcohol have been a struggle, but he is unable to pretend it didn't happen.

He told America's Playboy magazine: "Not having done drugs for literally five or six years is a lifetime. I think of myself as someone who has no desire, use for or conscious memory of that life. And yet I don't shut the door on it, and I don't pretend it didn't happen."

Robert has spoken candidly about his past addictions, claiming he was a "messed-up kid ... Lost, lost in narcotics", who has been fortunate to get through it unscathed.

He explained: "Looking back, I think, 'Oh my God, I could have been done. I could have been so fried and so bad off and, oh my God, such a cautionary tale.' And I still could be."

However, the 45-year-old star - who married movie producer Susan Downey in 2005 - believes that learning to be respectful has helped him combat his demons.

He said: "It's about respect. It's not even about self-respect; it's about respect for life and all it offers."

Robert now believes his years of sobriety - which have seen him appear in movies including 'Iron Man', 'Tropic Thunder' and 'Sherlock Holmes' - have been the best of his life.

He added: "My age and my recent set of experiences ... Have left me feeling I'm in the zone. This is just the sweet spot of my career and my life so far, and strangely, they've come at the same time."

Robert was arrested and attended rehab several times between 1996 and 2001 over his drug problems.

Source: Press Release