Sharon Osbourne once locked her daughter Kelly in a padded cell in a desperate bid to scare her into giving up drugs.
The 28-year-old reality TV star battled drug addiction for many years and checked into rehab seven times in an attempt to curb her behaviour.
Kelly admits her parents, Sharon and Ozzy, went to extreme lengths to stop her drug taking, but it wasn't until her mother was diagnosed with cancer that she decided to turn her life around.
She tells Britain's Cosmopolitan magazine, "I've been to rehab seven times and to two mental institutions. My mum even had me put in a padded cell once to scare me, but like a brat I just sat it out until she said, 'Well, that's not going to work.'
"But what I've learnt is that no amount of therapy or medication is going to work unless you want it to. Until you want to be a good person, you will never be one. What changed for me was looking around and seeing that nobody liked me or wanted to work with me...
"(When my mother was diagnosed with cancer) I was faced with the choice of a career or spending what could have been the last days of my mother's life with her. I said, 'F**k you, career, hello, Mother'. I became my mum's nurse 24/7. I thought I was going to lose her - it was awful."
Sharon, 60, won her battle against colon cancer in 2003.