Charlize Theron premiered her latest film, "Sleepwalking," which she stars in and also produced, at a special screening in Los Angeles on Thursday (March 6). The South African actress, who won an Oscar for playing a serial killer in 2003's "Monster," was on hand at the film's premiere, where she talked about the message parlayed in "Sleepwalking."

"I think it carries a philosophy that I really believe in, and that is, at the end of the day you have to be responsible for your life. I think we all come from family and from past, and we all, we don't necessarily have a choice in the matter of where we come from or what happens to us, but that at some point in our life we have to proactive to make decisions for the life that we want," says Charlize Theron, star and producer of "Sleepwalking."

"Sleepwalking" is about a dysfunctional mother struggling to raise a twelve year old daughter, who she leaves in the care of her brother for an extended period of time while she disappears with a boyfriend. In danger of losing his niece to foster care, the brother then takes off with the girl to head to his father's farm, where he finally addresses his painful family history. The film also stars Dennis Hopper and Nick Stahl, who both enjoyed working with Theron during production.

"Charlize is a very, a wonderful, creative producer," says Hopper. "She was there all the time, we were working very cold circumstances, like 25 below zero most of the time, wind-chill of sometimes 65 below zero, she made sure we were warm enough, put on extra long johns, and then she would be relentless about story and telling the story, and she's just a wonderful, creative producer.

"I almost said yes before I read the script, you know, I was like, I was always wanting to work with her and then I read it, and it turned out to be really great, and that's a bonus," says Stahl.

"Sleepwalking" will be released in the United States on March 14.