Kelly Osbourne, daughter of Ozzy and Sharon Osbourne, told BBC Radio 5 Live that genes are responsible for her former drug addiction. Her father had a long struggle with drug addiction, and Kelly says her DNA was pre-programmed to make her susceptible to addiction.

"I don’t have any shadow of a doubt that addiction is a disease. It is in your genes,” she said. "The only people in my family who don’t have that gene are my mother and my sister Amy. I consider myself lucky that I saw both sides of it. Drugs stop you from screaming on the outside, but you are still screaming on the inside.”

The 24-year-old has been in rehab four times and is presently drug free. “I was addicted by 16. Drugs stopped me from feeling a certain way. Some people experience euphoria but I never felt that. They numbed me and gave me confidence. It was like a magic medicine,” she said.

Kelly also admitted that she became a recluse during her lowest points of addiction. "I was plagued by feelings of misery and self-loathing. When I was taking drugs I didn’t shower or even brush my teeth. I just sat in my room on my own,” she said.

"I never admitted I was an addict. When I went to rehab it was like a college. We were taken to conference rooms and someone would explain about all different types of drugs and what they do to you. It made me think, ‘Why am I messing my life up?’ The only thing wrong with my life was me. I had two choices – keep taking drugs and die or I can stop."