Khloe Kardashian "passed out" at her father's funeral.
Khloe Kardashian
The 'Keeping Up With the Kardashians' star was devastated when Robert Kardashian lost his battle with cancer in September 2003 and blames losing him on her subsequent wild partying.
Khloe - who was 19 when her dad died - said: "At the funeral, when I saw my father in his casket, I completely fell apart.
"I don't remember the details, but apparently I was an emotional wreck, and I'm told that I was so distraught I actually passed out.
"At one point I fell to the floor kicking and screaming, and I had to be sedated. It was really intense.
"I refused to believe my father was gone. I just wanted to believe it was all just a bad dream.
"That's when the partying started."
Last year, the 31-year-old star had to cope with another big change in her life when her stepfather Bruce Jenner - who is now known as Caitlyn - announced he was transitioning to a woman, admitting she lashed out over the news because she felt so "hurt" by the loss.
She wrote in her new book, 'Strong Looks Better Naked': "It dawned on me that we never fully know other people, even the ones closest to us, and that we often make assumptions or pass judgement based on erroneous information or half-truths.
"Remember: hurt people tend to hurt people.
"That said, I was guilty of doing the same thing with Bruce. I had lost my father, and now I was losing Bruce.
"Bruce wanted to be a woman and I could only imagine the battle raging inside of his soul. My heart went out to him. But, I saw the transformation as a huge loss."
Tagged in Khloe Kardashian Bruce Jenner Caitlyn Jenner