Kelly Osbourne is re-writing her autobiography.

The 25-year-old star is revisiting 'Fierce' - which also contained self-help advice for teenagers based on Kelly's own life experiences - to include all the exciting things that have happened to her since it was published last September.

She said: "Last week I started a rewrite of my autobiography 'Fierce', which was released last year. The publishers and I have decided it could do with updating after everything that's gone on during the past six months, like taking part in 'Dancing With The Stars', and the cover photo needs changing too - I had black hair then."

Kelly - who has been in rehab four times to be treated for addiction to painkillers - admits she is more proud of book than any of her other career achievements.

She added in her column for Closer magazine: "I'm still really proud of my book, it gives advice to teenagers while telling my story of growing up."

In the first version of 'Fierce', Kelly spoke candidly about how she became addicted to Vicodin by the time she was 17.

The star - whose parents are Ozzy and Sharon Osbourne - first experienced the effects of the strong opiate when she had her tonsils taken out at 13 and three years later she was taking up to 50 tablets a day.

Kelly - who starred in reality TV show 'The Osbournes' with her family - wrote: "I was waking up and emptying six Vicodin into my hand. Soon I was taking 50 pills a day. Most people would overdose on 10. My friends called me 'Noddy' because I fell asleep all the time.

"My parents suspected. Mum would say, 'Darling, are you taking something? Please tell your mummy.' But I was good at lying."