Kelly Osbourne, daughter of rocker Ozzy Osbourne, has spoken of her slide into drug and alcohol abuse days after her release from a rehabilitation clinic.
Jack and Kelly Osbourne have both been treated for addictions
The 19-year-old said she turned to drink and drugs after finding it difficult to adjust to life in the US.
She was interviewed for ITV1's Tonight programme by her brother Jack.
She said she tried alcohol at 12 before using harder drugs and was constantly under the influence. "I was completely and utterly miserable," she said.
"Painkillers weren't the only drugs I did... towards the end, there wasn't a second in a 24-hour day that I wasn't high on something," she said in the interview.
Kelly and Jack Osbourne got a reputation for wild living following the success of their reality TV show The Osbournes.
Jack, 18, has also had treatment for drug addiction and was admitted to a clinic in Malibu, California.
Speaking about his own addictions, he said: "What no-one knew as I was filming the second series of The
Osbournes was that aged just 16 I was struggling with a serious addiction to a painkiller called Oxycontin or 'Hillbilly heroin'.
"My drug-taking made me so miserable that just months after this footage was recorded I tried to kill myself."
Kelly duetted with her father Ozzy on the number one single Changes
He said he had now been clean and sober since being released from the rehabilitation centre.
During the interview, Kelly said she felt driven to drink to escape her "chubby English girl" image after finding it hard to make friends in Los Angeles.
"In the beginning, you do it because it makes you feel good and then it gets to the point were it stops making you feel good and you do it because you don't
know what else to do," she said.
During the Tonight programme, to be screened at 2000 BST on Monday, parents Sharon and Ozzy talk about their guilt about their children's problems.
Ozzy said: "We were in denial. You always want to think it's somebody else's kids, not your own."