The very notion of a film about sex addiction will turn off some people, but British director Steve McQueen’s “Shame” is a serious study of the subject. It centers on Brandon (Michael Fassbender), a New York yuppie whose obsession with sexual activity inhibits his ability to build a satisfying emotional relationship. It’s the second film the two men have collaborated on, a follow-up to “Hunger,” McQueen’s debut feature.

In a recent Dallas interview, McQueen explained the genesis of the project. “I’d seen this Pasolini movie where a character slept with an entire family,” he said. “This visitor came to the house and slept with the mother, the father, the sister and the brother. So I put it away. Fast forward two and a half years later, I had a conversation with Abi Morgan. And in that conversation we started talking about the Internet and pornography, and we got off on the subject of sex addiction. And alarm bells went off in my head. This is the subject—this is what I want to investigate. And from there we tried to actually interview people in London. I was almost like Miss Marple and Columbo, detectives on the trail of sex addiction. That was a dead end because at that time no one wanted to speak to us. At the time in the media sex addiction was very much in the public eye, and it closed a lot of doors. No one wanted to speak to us.

“So then I wanted to talk to experts in the field. And the two experts we found were in New York. We went over there and had conversations with them, and they in turn introduced us to sex addicts and people who were suffering the affliction and people who were recovering. Sex addiction is not about being promiscuous. This is all-encompassing. This is a situation where the addiction dictates the person, controls the person. The addict, the person afflicted, has no choice. And that was the seed, and I thought, okay, let’s shoot this in New York. And that was it.”

Did Fassbender, whose career has soared in mainstream films like “Jane Eyre” and “X-Men: First Class,” balk at the thought of playing a sex addict? “Never,” the actor said. “The thing is, I’m in the business of storytelling. I’m there to facilitate a story. Now whether that story involves mutants or real-life people, the respect I bring to it doesn’t really vary. And what I don’t think is how is this going to damage Michael Fassbender. I’m thinking about my job as an actor. It’s not to worry about how an image is portrayed or any of that—it’s ‘Can I facilitate the story?’ Now, would I have done a story like this in somebody else’s hands? I don’t know. [With Steve] I knew that I was going to be in the best hands possible. The trust between us is really beyond a hundred percent. Then it’s just whether I’m going to hold up my end of the bargain. That’s really where the nerves come in, and the fear. Am I going to be able to represent Brandon the correct way, am I going to be able to bring to the table something that’s going to help Steve and Abi? They’ve written this beautiful story, and my part to facilitate it in my area. All the other stuff is just distraction. I keep it really simple.”

“He’s an artist,” McQueen interjected. “What I mean by that is that he’s looking for something to facilitate it, as an artist does. It may be high, it may be low—where the goal is, he’ll go. That wasn’t rhymed, was it?” he added to general laughter.

“Really, nothing changes,” Fassbender continued about his new-found fame. “It’s exciting, and it’s nice, but my day-to-day routine, or activities, haven’t changed at all. What has changed, and what is amazing, is the choice. When you have filmmakers that are interested in working with me that I hold in high regard—very talented people—that is just the pinnacle, the dream. At one point you’re just happy to be a jobbing actor, that’s good enough. So to be in this position is…crazy.”

And, Fassbander said, this script moved him. “I felt for [Brandon] and really liked him, and thought it was a beautiful insight into something that I really didn’t have any knowledge about. I didn’t really take [sex addiction] seriously, and then you start to investigate and you meet people and you realize just how devastating it is. And the thing that struck me was how Abi and Steve had created these characters that I really cared about.”

“This is a responsible film,” McQueen emphasized. “I wouldn’t do a horror film where people get chopped up into pieces and out in a frying pan. I find that very irresponsible filmmaking. I think what the cinema screen is, in some ways, is a place where we can actually see ourselves and can actually have some idea, or gauge ourselves in some way, of where we are and how far we’ve got to go.”

And like Fassbender, he McQueen also pointed to the level of confidence he had in their collaboration. “It’s all trust, really. It’s a dream come true when you’re collaborating with someone, pushing and challenging each other, and it coming off. I was a bit naïve—I thought every actor was like Michael. But they’re not. He’s exceptional. He just transforms and transcends the character. He has that chameleon [quality]. He’s just amazing.”

Fassbender immediately returned the favor. “It’s all in the environment [Steve] create[s],” he said. “I think the first thing that struck me when I met Steve is that he’s a very honest, open person, so it’s all right to be vulnerable and insecure or feminine or nerdish—all the things perhaps we try to disguise because we’re afraid of ridicule. These are all things I think we can relate to. It’s the passion—Steve’s a very inclusive person, and everyone [on the set] believes, right down to catering, that they’re part of something together. Then you have a force that’s collectively really effective and powerful.”

McQueen pointed to a crucial scene in “Shame,” in which Brandon attempts to develop a real emotional connection with a work colleague he invites out to dinner, as the key to understanding the man’s personal torment—and the truth about his addiction. “He yearns for that kind of relationship,” he said. “On the stroll back, he lets his guard down, and you get an insight into the possibility of a relationship there. I think that’s the tragedy. There’s warmth there, there’s a childlike element to him, but to take it to the next level is just too much.

“When Marianne and Brandon attempt to make love in the hotel room, it’s a situation where we have to see Brandon attempt to have contact, have communication with a woman in a way that is sharing, that is giving—lovemaking that is give-and-take. What we’ve seen of Brandon up until that point is very much taking, because of the addiction, the affliction. [This scene] is all about seeing them attempt to humanize themselves and be intimate with another human being. When that collapses, it’s tragic.”

As to whether “Shame” will attract an audience, McQueen professed an inability to predict, though both he and Fassbender remarked on its similarity to American films of the seventies and their belief that audiences were still looking for challenging, intellectually stimulating fare. “I want to tell the story. If it’s marketable or not, I don’t know. Hopefully, possibly,” he said. He joked about the picture’s NC-17 rating, saying that when he’d heard about the term, “I thought it was a rap group.” Fassbender added: “This seemed important, this seemed relevant, and you feel passionate about something. You have no idea whether others are. But you believe in something, and you want to make it. And then you let go of it and see how people respond. The fact of the matter is that there are no rules in this game.

“All I care about is that people are allowed to see the film,” McQueen concluded. “I respect the rules, as long as it doesn’t prevent people from going to see it—that’s all.”