Barrymore, 39, said her friends had become her family while she was growing up, reported Variety.
"I appreciate that terms like 'modern family' and 'blended' have become familiar in the culture as ways to describe a pride in a family that doesn't look a certain way.
"I think that my family looks traditional from the outside, but I also know that I had kind of 'zero-point-zero' family growing up, and it was my friends that became my family and they gave me a sense of place in the world and they gave me tough love," Barrymore said.
Barrymore believes families are supportive and honest and have no rules.
"I think there are no rules. I think of family as where you feel safe. It's where you feel supported, and it's where people are being deathly honest with you," added Barrymore.