Mila Kunis has admitted fame has made her less trusting as she wants to protect her privacy.
The 30-year-old actress - who is currently expecting her first child with fiance Ashton Kutcher - admitted she could relate in some respects to her character in new drama Third Person - a mother fighting to regain custody of her son.
Mila said: "It's so sad to say but I didn't mistrust people as much as I do now.
"Now I go into a friendship with somebody and I automatically think that I should have my guard up and it's a Heisman [fake] friendship until proven otherwise.
"And it's a horrible place to start, because you should want to start a friendship with full trust unless proven otherwise, and the opposite... yeah, it happens."
The Black Swan star added it was not just being in the movie business that made her feel that way.
She said "It's business and life. I think the more life you have the more life you want to protect, and the less you want to let people in."
And Mila is happy with the friends she has.
She said: "I have a handful of amazing girlfriends - I'm good, I'm done. I don't need any more. I'm very lucky. I literally can count on one hand my bestest friends who would give me everything and anything, and I would give them. I don't need more - I'm OK.
"I don't come from a school of thought where I need 100 friends and then I'm worth something. I don't need more. I'm good with my five."
Mila stars alongside Liam Neeson, Adrien Brody, Olivia Wilde, James Franco, Moran Atias, Kim Basinger and Maria Bello in romantic thriller Third Person, directed and written by Paul Haggis.
It follows three overlapping relationships in Paris, New York and Rome. Mila's character is based in New York and is fighting to prove she did not attempt to kill her son, and win back custody from her husband, played by Franco.