Ellen Burstyn says she’s too sick to shake hands. And when I meet Darren Aronofsky, who’s just getting over a cold, he’s anxious, jittery, waiting for his cell phone to ring. It’s been months since they finished production on Requiem for a Dream, and I’m talking to them in two different cities, days apart. But considering the staggering intensity of the film they’ve made together, it’s not hard to imagine the two are still reeling from the aftereffects.

In the film, adapted from Hubert Selby’s novel, Burstyn plays Sara Goldfarb, a lonely Coney Island widow whose obsession with appearing on television becomes so all-encompassing that she starts crash dieting, just in case she needs to look thin for the cameras. When eggs and grapefruit don’t do the trick, she switches to diet pills, and before long, she’s a full-blown speed addict, so delusional she thinks her refrigerator is trying to bite her head off. Her son Harry (Jared Leto) is the only one who realizes exactly what his mom’s been swallowing, but since he’s a heroin addict in the middle of a dope draught, he’s got problems more pressing than weaning his mother off pills. With no one to set her straight, Sara sinks deeper and deeper into her own fantasies, and even at the movie’s wrenching conclusion refuses to face the shambles she’s made of her life.

It’s a grueling role for any actor, let alone a 67-year-old Oscar winner, and Burstyn admits she was reluctant to take it. "I wasn’t so attracted to the role at first," she allows, sipping herbal tea and wrapped in scarves in a New York hotel. "At the time, I was working on Mary Tyrone in Long Day’s Journey into Night at the Hartford Stage, and I was deep into addiction and emotional turmoil, unhappiness — working for nothing. I’d just done The Yards, which was a low-budget movie, and I was waiting for a movie offer to come along which was a big-budget movie, an attractive role, with some lightness and humor. And along comes this dark script, and I thought, My God, I don’t want to put myself through this. And I was prone not to do it."

But before she turned down the role, Burstyn figured she’d better take a look at π, Aronofsky’s first feature. "I’d heard it was really good," she recalls, "and as soon as I saw a few frames of it, I went, ‘Uh oh, what’ve we got here?’"

It’s not the first time the veteran actress has thrown her weight behind a fledgling director. In 1973, Burstyn — who, coming off The Exorcist, was at the height of her box-office clout — hand-picked a 31-year-old Martin Scorsese to direct her in Alice Doesn’t Live Here Anymore. (Never one for predictability, she took three years after she won the Oscar for Alice before her next film.) Aronofsky is 31 as well, and if the similarity in age is a coincidence, Burstyn’s reasons for working with young directors remain the same.

"It’s always been a favorite of mine to work for people when they’re still hungry and full of enthusiasm for their art form," she explains. "Sometimes people get very wounded by the business, and they become cynical and their talent suffers. I like to work for talent when it’s young and fresh and new and full of passion, and hasn’t gotten jaded yet."

Jittering away in the lobby of a Philadelphia hotel, Aronofsky seems anything but jaded. If he seems less focused than his last visit here two years ago, it’s probably because it’s only a few days after Variety broke the news that he’s been signed to write and direct the next film in the Batman series, and the details of the deal are still being worked out. Still, he’s cogent enough to remember how he felt when a woman who’d been making movies longer than he’d been alive stepped onto the set.

"I was terrified of her," he recalls, then recants, "not terrified, but in awe. Very, very quickly, though, we realized that we were able to communicate. And she very quickly learned that the way me and my team made movies was with a lot of care, and with a lot of passion. She got excited by that, and we had a great rapport and trust. It was a real blessing. The best thing I’ve ever been involved in is capturing her performance in this movie."

Requiem had been a dream project of Aronofsky’s since college, where, as he tells it, he blew off his Harvard exams after finding a copy of Hubert Selby’s Last Exit to Brooklyn in the library. "I didn’t know anything about it," he says, "but when you’re a Brooklyn kid at Harvard and you see a book about Brooklyn, you get interested." Later, while attending film school in Los Angeles, Aronofsky made a short film out of one of Selby’s stories, and struck up a friendship with the author in the process.

The script for Requiem evolved through a curious process. Selby told Aronofsky he’d written his own adaptation in the ’70s but had lost it, so Aronofsky set about crafting his own version. It wasn’t until he was "80 percent of the way done" that Selby located his old version in his mother’s basement. After comparing the two, Aronofsky discovered they’d focused on many of the same scenes, so he "fused them together, and we would go back and forth. He would give notes, I’d make adjustments, and eventually we arrived at something we were both proud of."

The novel proved difficult to adapt, Aronofsky says, simply because it was difficult to establish a point of view. "When I structure, I draw it out like an arc," he explains. "I draw each character point so I can see how the character’s arc works. I was trying to figure out who the hero of Requiem for a Dream was, and every time something good happened to one character, something bad happened, so [the arc] was like a frown. I was looking and I suddenly had this moment of clarity. I flipped it over, and I realize that their enemy, their inverse was actually the hero of the film: which was Addiction with a capital A, and that this movie was a film about Addiction conquering the human spirit. So basically when we executed the film, we looked at every scene and tried to say, ‘Where is Addiction in this scene?’ Our invisible hero."

If that sounds a bit pedantic, it doesn’t show in the film, where Aronofsky’s concepts are realized with subtle grace. But according to Burstyn, there’s a conscious plan behind every shot. In one scene, Leto and lover/fellow junkie Jennifer Connolly lie next to each other in post-coital bliss, and they appear to be facing each other from opposite sides of the bed. But we soon realize that what seemed like one shot is actually two carefully matched split screen images which shift as each explores the other’s body. "I think that’s breathtaking," Burstyn testifies. "I said to Darren, ‘Why did you do that? Why not just have a double shot of the two together? He said, ‘It was my way of showing that they’re together, but they’re not really together.’ I think you can go through every one of Darren’s shots and ask him why he did it that way, and he would have as clear an answer."

Aronofsky admits to being "pretty compulsive" about his work, so it’s only appropriate that Requiem, like π, is about people whose compulsions take over their lives. (Batman: Year One, the Frank Miller comic Aronofsky’s chosen to adapt, continues the focus on compulsive behavior.) "It’s probably a reflection of me in some way," he ventures. "I just find it very human. It’s like the fight against entropy, to make order in the world before we all decay into nothing."

If Aronofsky comes off like a filmmaking junkie, Burstyn has her compulsions as well. She talks about "the flow," the feeling of a perfect performance, "when you’re not doing it but it’s doing you. That," she smiles, "is addictive. That’s truly addictive. But in a good way. That keeps you coming back."