Wild child Kelly Osbourne says she and brother Jack can thank their rock 'n' roll parents' genes for their drug problems.

Kelly, 20, says she and Jack, 19, inherited genetic weaknesses from their parents, Ozzy and Sharon, which made the siblings more likely to be drug addicts.

"I think addiction is a genetic thing," Kelly told The Sun. "You are born with it and people don't understand that."

Kelly was treated last year for an addiction to painkillers and her mother hired someone to travel with her daughter to keep her off alcohol.

Despite criticizing her parents, Kelly told an Edinburgh, Scotland, radio station that fear of losing her father in a 2003 motorcycle crash was "one of the most tragic moments in our entire lives."