By ANGELA DAWSON

Front Row Features

HOLLYWOOD—Maria Bello has had such a long and storied career that it’s difficult to pick out just one memorable performance. To some, she will always be synonymous with Dr. Anna Del Amico from NBC’s “ER.” For others, she is the loving wife from David Cronenberg’s “A History of Violence,” while others recall her for her comedic turn in Adam Sandler’s “Grown Ups” movies. Bello also is a long time activist, having started her first NGO, The Dreamyard Drama Project, in Harlem in 1997. Since 2010, she’s been working with other celebrity-activists in rebuilding Haiti, following the devastation earthquake that leveled much of that Caribbean country’s capital. Her organization, We Advance, advocates for women throughout the country to have full political, economic and social participation.

Last year, the outspoken and openly bisexual actress published “Whatever … Love is Love,” a memoir about family, partnerships, sexuality and spirituality.

Bello, 49, now stars in the psychological thriller “Lights Out,” as a recent widow suffering with schizophrenia, who has somehow conjured a horrific entity from her childhood. As Sophie, she is trying to be a good mother to her school-age son, Martin (Gabriel Bateman). But as she tries to wean herself from strong medication, the mysterious dark entity resurfaces at her house. Her estranged daughter, Rebecca (Teresa Palmer), comes to help along with her boyfriend Bret (Alexander DiPersia). But Diana, as the entity is called, may be too strong for this extended family to fight off, especially when the lights go out.

The film marks the directorial debut of David F. Sandberg, who based the film on his 2014 short film of the same name. “Lights Out” was fleshed out into a feature length script by Eric Heisserer (“Final Destination 5”) and is produced by James Wan (“The Conjuring”) and Lawrence Grey (“It Follows”).

Bello, who hails from Norristown Pa., spoke about taking on such a physically and emotionally demanding role and how personal experience came into play in depicting her character in a very grounded way.

Q: This is a dramatic movie with horror layered on top, and is an allegory of mental illness. What got to you about that premise?

Bello: That’s exactly how I felt when I read the script. If you took the horror out of it, it’s a stand-alone movie. The drama of this family and these complicated relationships due to mental illness. I was certainly drawn to that. She’s a wonderful character to play, a mother suffering from depression, off her medication, on the verge of a psychotic breakdown, who also has this shadow self. You don’t know if it’s real. She doesn’t know if it’s real at some point. I thought that would be a complicated and great thing to play.

Q: How did you prepare for the role?

Bello: I prepared through lifelong of living. Some of you might have read my book where I talk about having the gift of bipolar disorder. I was able to use my experience from that and put it onscreen for the first time. Remembering what it was to be that person who couldn’t get out of bed for three months, to really try and understand what it would be like to have my child at a time when I was in that space, and not understanding what reality was.

Q: Your co-star Teresa Palmer said she was relieved that you were going to be playing the mother in this. She also had first-hand experience with a mother with mental illness issues. What was it like working with her?

Bello: I really dig her. She’s just a cool woman. As soon as we met in the trailer, it was like five minutes before our scene and we were like, “Hi, mom!” “Hi, daughter.” She’s with her little kid and I’m getting my son organized for soccer, and we just went in and did our scene. She’s like an Aussie Earth Mother (type), really genuinely in herself, and in a second she turns on this American accent and puts on this tough-girl thing and just does the work. She’s really good. I look forward to working with her more in a different capacity.

Q: Diana is the only person who understands you. You don’t usually see that kind of connection between a demon and a human in a movie. Can you talk about working with Alicia and finding that connection?

Bello: First of all, have you seen Alicia? She’s a supermodel. She’s a gymnast that looks like a supermodel. It’s funny because she’s really soft-spoken. I do believe at Comic-Con next year, there will be people dressed like Diana because she’s so creepy, the way that she moves her fingers and squats. That’s all her imagining this entire character without speaking, without ever being seen, really, only in the shadows. So I think she did a terrific job.

Q: Is there a trick to acting in a movie that’s so severely dark and light?

Bello: Yeah. There was that one scene where I’m talking to a closet and you don’t know whom I’m talking to, the truth is there was nobody there. So I’m kind of in the dark talking to myself in the dark. It was interesting. It was interesting to shoot a scene or two with just a candle. I love the lighting in this film and the not lighting in this film. David captured that on his three-minute video. The reason why they found this film and did it, it has more than a million hits. He was able to do it on a low budget and in such a practical way. No one ever guesses that Diana isn’t CGI. You don’t know it’s practical and most of the lighting is practical.

Q: How was David as a first time director?

Bello: He was wonderful. He’s had no ego about him. He’s like a little kid coming to Hollywood going what the heck am I doing here. He had a strong vision of what he wanted. You could tell by his other shorts. He has a real passion for film. When you speak to him, his passion just shows through. He just collected the greatest people around him. Lawrence (Grey) and James Wan are at the top of the genre and the DP and the production designer and the actors. He was open to having the best people come together to make his vision come to life and I think he did a terrific job.

Q: Did you have any second thoughts about this film because it is a horror movie?

Bello: I’ve been offered these genre films in this budget range. A lot of people are trying to do them now after the (Jason) Blumhouse model started. I’ve never done them because they never interested me. But when I read this character … I have such great agents. My one agent, particularly, no matter what the budget of a film, she’ll read (the script) if it’s offered to me and say, “This is a great part.” She called me and said, “This is a great part.” And I read it and went, “Yes! This is a part I want to do.”

Q: Do you have an affinity for particular horror films?

Bello: No. I think the last horror film I watched was “The Exorcist.” I was like 12. I don’t really like horror films. I love thrillers. I can’t wait to see “The Girl on the Train.” I loved the books so much and I thought, “Is this going to be a movie?” And then I saw the trailer for the movie.

Q: Have you seen the completed film yet?

Bello: Yes, and I was scared. Remember, I wasn’t in the first sequence with the mannequins in the warehouse so that was all new to me. (My friend) was screaming so loud. We were grabbing each other. I don’t usually sit through a movie at a premiere but I’m going to this time because I can’t wait to see it with an audience. I heard it’s hysterical to see it with an audience.

Q: What did you make of Diana, the evil entity in this film?

Bello: I see her as part of my psychology. In terms of being a mutant, a real spirit or a person, I’m not sure. But I love the ending. I think it’s a real twist that you don’t usually see in a film.

Q: When was the first time you saw Alicia Vela-Bailey, who plays Diana, in makeup?

Bello: It was in the trailer when I saw her getting her prosthetics on. She had six different layers of prosthetics. She had to eat and drink standing up. I don’t know how she went to the bathroom.

Q: As an actor, were you happy that Diana was not just a special effect?

Bello: I didn’t know beforehand. I thought they might put a lot of CGI in it. But it was so well done with her and the lighting they had. They didn’t need it.

Q: Teresa said she was protective of Gabriel Bateman, who plays your son Martin, on the set. Is that the way you were with him?

Bello: No, not at all. Gabriel is like older than me. He’s a wise soul. There’s nothing child-like about him. He’s like a guy. It was like working with an adult actor in a lot of ways. I just didn’t think of him as a little kid.