Linda Blair was only 15 when she was catapulted into worldwide fame as Regan, the possessed girl at the center of William Friedkin's "The Exorcist." Upon its release, the teenager received both Academy Award and Golden Globes nominations as well as a slew of death threats from outraged protesters who denounced the film as heretical and blasphemous.

Since then, Blair has starred in a number of movies and founded the Linda Blair WorldHeart Foundation, an organization aimed at increasing awareness of animal abuse and helping neglected animals find new homes. With the release of "The Exorcist Extended Director's Cut," featuring three documentaries that give an unprecedented look behind the scenes of the classic film, Blair talked to NextMovie about her media vilification, religion in America and why you shouldn't call "The Exorcist" a horror film.

In the behind-the-scenes documentary, we see a completely different side of "The Exorcist" in that the set is friendly and genial and William Friedkin, who has the reputation of a surly dictator, acting almost like a surrogate father to you. Can you talk a little about the vibe firsthand?

For so many years, it was more fun for people to make up stories and myths about the set. But nobody could understand or acknowledge what it was really like. Finally, after this many years, people can see that it was really a professional set and this is finally allowing me the freedom so people can look at the movie and see a professional child actor in a professional work environment.

And with all of the technical parts of the film, there was no fluidity to it. It wasn't like doing a play. When Billy Friedkin put in the sound and the music and the special effects, a lot of people don't realize how much he assaulted their senses. But for me, on the set, it was fun, but it was still a job.

Did people on set know they were making a movie that would have this much influence or did it feel like just another film?

Oh, I'm pretty sure Billy Friedkin had every intention in the world that he was going to outdo his Academy Award with "The French Connection." When you hear ["The Exorcist" novel's author and film's screenwriter] Bill Blatty and Billy Friedkin talking, they tell you the story of just trying to get this movie made. Everyone wanted to ban the book, and then nobody wanted to touch the movie because this was just a horrible topic to touch on. Then it got passed on from director to director. There's so much that went on just to possibly get the film to a position of starting pre-production.

With the Blu-ray, people will finally physically see us smiling. They see all the equipment, the cameras, the lights. They see me just hanging out, they see the hospital scene which terrified them and I'm just sitting there in my position waiting for everything to get set up, and you realize it's just technical. Then you put it all together. That's where the final mastering is where Bill could put the final pieces of the puzzle together.

You mention in the documentary that because of your age and religion [Blair was raised Protestant and barely familiar with the concept of Satan], the more controversial or terrifying scenes didn't have much of an impact on you when filming them. At what age did you first start to realize the intended meaning of the film?

Write this: When I was 15, they used to have huge press conferences. There would be 250 or 500 journalists sitting in front of me and they would put me on a dais. I would look out to a sea of questioning eyes from adults saying, "What about God and the devil and religion and what do you think?" There was a lot of fear. They really thought that I could answer all these questions. And I would honestly answer, "Well, if there's good, there's evil. If there's God, there's the devil, I guess. But for me it was just a fictitious creature." I'm like, "I'm 15 years old. Are you serious?"

Do you think there was also an air of condescension as if to say, "How could you put this child through that?"

Oh yeah, totally. When the movie first came out, no one thought it would become the film that it's become 37 years later. But most of all, we were all attacked in every way. Friedkin had to spin the machine and turn a lot of things around.

Are you surprised that nearly 40 years later, you're still doing interviews for this?

In anybody's wildest dreams, it's almost an impossibility. But I'll tell you what I think: since the beginning of time, war has always been fought over religion. We are in that time right now. There was a conversation about a week ago -- I didn’t start this conversation -- about America becoming religiously illiterate. With all of the religions, everyone is talking about "my religion."  If everybody could just respect people and their beliefs, but when it comes down to it, you ask people certain questions, no matter what it is, and they may not be able to answer about their own religion. They may go to church or temple once a week, but do you live your life every day like that? I live my life every day with giving back and doing my charity work. Are we in any different position than we were thousands of years ago? That's what I want America to think about.

You've referred to "The Exorcist" as a "theological thriller" rather than a horror film. Why? Do you think the term "horror" has negative or incorrect connotations?

Well, this movie, to this day, is a highly intelligent theological thriller. I want the audience to listen to the words. It's about losing this faith. It's about these different emotions that people have. This movie was ahead of its time and it still addresses these issues. Let's look at it and think, what's happening in the world right now? There's something more to it and I'm just starting to put my finger on it. I'm not controlling this movie. The audience is what's controlling this film. You know that, right? Do you know that? The movie has its own life. It's not just a "scary movie." This is what Linda says: sit in your office and contemplate. The movie has to have more to it than even some of us realize.

You've been open about your past troubles with drugs and ability to get clean. What advice would you give young actresses dealing with the same pressures and excesses you went through?

I would tell them do something that's earthy and real. You must get back. They say don't forget where you came from. Give your time and volunteer. It fights depression. There is no depression when you give your time and see others in worse positions that you're in and you can help them.

Switching gears a bit, you devote a lot of your time to animal rescue. Has this always been an interest of yours?

I wanted to be a veterinarian when I was growing up. My mom said if you work and save your money and stay independent, you can do what you want in life. So years later, I'm doing exactly what I wanted as a child. I couldn't be a veterinarian, but I'm helping animals around the world the best that I can. "The Exorcist" has given me a platform and people have become more curious [about man's treatment of animals].

At this point, NextMovie wanted to confirm or deny the longstanding rumor that Rick James, who Blair dated in the 1980s, wrote his hit 1983 song "Cold Blooded" about the actress. While Blair had to continue doing interviews, her publicist replied via e-mail later that day, "It is true." One of rock's mysteries solved.