Natural Born Killers star Robert Downey Jr is fed up of people quizzing him about his past drug problems. The actor was arrested numerous times in the 1990s and early 2000s for drug offences and has spent time in both a state penitentiary and rehab. He says, "The subject's not off limits, but it's been three years of literally nothing but that. "I want to talk about it, but my assignment's to talk about the movie, not the Partnership for a Drug-Free America. It doesn't upset me, but it can distract me from where I'm at now. "Unless you see me running down Melrose naked with a bottle in my hand or I get arrested again on narcotics charges, there's nothing left to discuss."