Celebrities Reveal Surprising Pasts

Just when you thought nothing could surprise you. In her new book, "High on Arrival," Mackenzie Phillips claims that she had a sexual relationship with her father, John Phillips, who was a member of the '60s Mamas and the Papas band." Phillips, who starred on the TV show "One Day At a Time," writes in the book that she had sex with her father the night before her wedding in 1979 to Rolling Stones entourage member Jeff Sessler. She says the sexual relationship with her father continued for years after that first night which she called "rape."

"My father was not a man with boundaries. He was full of love, and he was sick with drugs. I woke up that night from a blackout to find myself having sex with my own father," she writes in the book. Phillips also appeared on "The Oprah Winfrey Show" to discuss her relationship with her father, who died in 2001. She told Winfrey that her father also shot her up with heroin. Phillips has struggled with drug addiction in the past and was arrested last year for cocaine and heroin possession at Los Angeles International Airport. She pleaded guilty, and was ordered to enter a drug rehabilitation center.

VIDEO: Mackenzie Phillips talks to Oprah about being raped by her father.Play

Phillips' bombshell is just the latest in a long line of celebrity revelations. Here are some of the most shocking.

Anne Heche

Anne Heche's book "Call Me Crazy" explains many of the actress' low points in her life. She claims that the sexual abuse she suffered at the hands of her father Donald Heche caused her to escape to a "fourth dimension." "I'm not crazy," Heche told Barbara Walters in a "20/20" interview. "But it's a crazy life. I was raised in a crazy family and it took 31 years to get the crazy out of me." She described the abuse from her father, saying, "He raped me ... he fondled me, he put me on all fours and had sex with me." She qualified the abuse by saying it is only "in my memory."

Her mother Nancy Heche responded to her daughter's accusations on a Web Site called Previewport.com, saying, "I am trying to find a place for myself in this writing, a place where I as Anne's mother do not feel violated or scandalized. I find no place among the lies and blasphemies in the pages of this book." Heche claims that as a result of the alleged abuse, she developed an alter ego, which she called Celestia, whom she believed was a reincarnation of God. "You name it, I could do it. I could see into the future. I could heal people," Heche told Walters. "I don't know where it came from. I was, in my mind, learning it from God." Heche believes that the memoir helped to bring her closure on many of the issues she faced in life. She says she wrote "Call Me Crazy" to say goodbye "once and for all, to my story of shame and embrace my life choice of love."

Rosie O'Donnell

Rosie O'Donnell shocked many when she revealed that she used to break her bones as a child with baseball bats or hangars. In her memoir "Celebrity Detox," she writes "[I broke] my hands and fingers usually. No one knew. It was a secret."

She explains she did it because it was "proof I had some value, enough to be fixed."

She also writes about the fear of abandonment she experienced after her mother Roseann died of breast cancer when O'Donnell was 10 years old. O'Donnell also released a part-memoir, part-mystery book called "Find Me" in 2002. The book delves into O'Donnell's troubled childhood, as well as her relationship with a woman suffering from multiple personality disorder. I was an abused kid," she writes. "This is something I've chosen not to dwell on in my public life. It sounds trite, like an 'ET' sound bite. However, sometimes you can't escape a cliche. So yes, I have been abused," she told Diane Sawyer in an interview.

Barry Williams

Barry Williams, known as Greg Brady on "The Brady Bunch," revealed in his book "Growing Up Brady" that he went on a date with his TV mom Florence Henderson when he was 15 to the Coconut Club in Los Angeles. "I could've ended up writing a book that was about as interesting as the Brady shows themselves,'' he told Entertainment Weekly.com. ''But there is drama, there is conflict." Henderson, who was married at the time, has publicly stated that the date was platonic. "When I wrote the book, I was very specific about how the date was because I felt it was a very significant part of my growing up … I definitely, definitely was on the make for my television Mom. But she, on the other hand was, I think, flattered by the attention and great innocence attached to it. I think she could see my struggles as a teenage kid, there was no doubt that she was married, had four children of her own, and the relationship -- despite what I wanted and where I wanted it to go -- was never going to go anywhere," he said on his Web Site Barry Williams.com.

He also claims he went on a date with TV sister Maureen McCormick as well. "Maureen and I dated on and off from year three through year five. We liked each other, trusted each other and of course it was convenient. It got kinda weird, though, because of all the people, parents, producers being around all the time, not to mention the roles we played," he said.

Charlize Theron

Actress Charlize Theron has spoken in the past about witnessing her mother kill her father when she was 15. Theron's mother Gerda allegedly shot her husband Charles, who was an abusive alcoholic, in act of self-defense. Her mother was never charged. "Everything changed for me the day my father died. Years ago I used to cover it all up and say he died in a car accident. I have now come to terms with it and have been able to move on. This was so long ago in my life and my life, my emotions and the pain are not stuck in this one event," Theron said. She recently told Vogue magazine that although she has come to grips with the traumatic experience, she still wears the incident like a "tattoo."

Chaz Bono

Chastity Bono, daughter of Cher and the late Sonny Bono, announced in June that she will now be known as "Chaz." The 40-year-old child star is planning to undergo gender reassignment surgery. "Yes, it's true -- Chaz, after many years of consideration, has made the courageous decision to honor his true identity," read a statement released by Bono's publicist at the time. "He is proud of his decision and grateful for the support and respect that has already been shown by his loved ones. It is Chaz's hope that his choice to transition will open the hearts and minds of the public regarding this issue, just as his 'coming out' did nearly 20 years ago." Bono, an LGBT civil rights advocate, journalist, author and musician, began the process of changing his gender earlier this year, following his 40th birthday. Cher released a statement to Us magazine that "Chaz is embarking on a difficult journey, but one that I will support. I respect the courage it takes to go through this transition in the glare of public scrutiny, and although I may not understand, I will strive to be understanding. The one thing that will never change is my abiding love for my child."

Bono revealed to his parents that he was a lesbian at age 18 and wrote about the experience in his 1998 memoir, "Family Outing." In 2002, Bono wrote "The End of Innocence," a second memoir about coming out, his music career, and his partner's death from non-Hodgkin's lymphoma. According to Bono's books, Cher was shocked by the news of his sexuality and even banished Bono from her NYC apartment immediately after he came out.

Roseanne Barr

In Roseanne Barr's book "My Life as a Woman," she writes that she believes she suffered from multiple personality disorder at certain times in her life. "Maybe I didn't. And maybe I was like from an alternate universe or something. And I've always felt like an alien. That's all I know.

And several times I wondered if I had multiple personality disorder, in fact, or if I was just from another,"she told Larry King in an interview. She also says she has been the victim of sexual abuse, a claim which both of her parents and siblings have denied.

David Cassidy

David Cassidy startled "Partridge Family" fans when he revealed that he once slept with his TV sister Susan Dey. Cassidy says that he was never attracted to Dey, but she was so determined to sleep with him, that he gave in. He told the Globe, "I find a certain sluttiness very attractive in a woman, and Susan just didn't have it. She was sweetness and innocence, a good girl, and I couldn't think of her as anything but my sister."