Drew Barrymore's Diaz support

Jan 14, 2009, 4:00 GMT

09/25/2008 - Drew Barrymore - Drew insists her unconventional upbringing did not properly prepare her for adulthood. © Janet Mayer / PR Photos

Drew Barrymore's friendship with Cameron Diaz helped her overcome her troubled childhood.

The 33-year-old actress insists her 'Charlie's Angel's' co-star helps keep her sane and is one of her closest confidantes.

She said: "Cameron's one of the greatest friends anyone could ever have. She has so much love and positive energy to her. I've always felt like she's my big sister. "

'Beverly Hills Chihuahua' star Drew had a troubled childhood - by the time she was 15, she had survived a suicide attempt and several stints in rehab. At 16 she was legally emancipated from her parents, Jaid and John, and living alone.

Drew insists her unconventional upbringing did not properly prepare her for adulthood.

She said: "My father was literally out of his mind and my mother was more like a friend. She'd take me out to clubs and I wound up feeling like part of this very unreal kind of world.

"I didn't have the kind of childhood which would have given me any perspective on what a happy home life or relationship would feel like. It left me without any bearing when it came to how to live in general."

But the Hollywood beauty - who shot to fame when she appeared in Steven Spielberg's blockbuster 'E.T The Extra-Terrestrial' aged seven - has now forgiven her parents.

She added to Britain's OK! magazine: "You can't go through life blaming your own failure on your parents and what they did or didn't do for you. You have to take responsibility for every day you wake and decide what you're going to make of your world."