The absolutely dazzling smile that occasionally flashes across Anna Paquin’s face hardly reflects the roles she’s been playing. In the theater, where the actress is mostly working these days, she’s created a niche portraying a string of sullen, troubled lowlifes.

Take, for example, Shari, a chain-smoking young mother (no surprise: unmarried) in soulless suburbia who’s trying to have sex with her adolescent stepbrother and is having it with her mother’s creepy boyfriend. This is Paquin’s character in “The Distance From Here,” by Neil LaBute, who’s made a name for himself creating unsettling sorts. The type of scum, he writes in the playbill, to whom he would “probably give … wide berth if we ran into each other in McDonald’s.”

‘Emotionally exhausting’

LaBute is hardly the only playwright dealing with the genre – as Paquin well knows. She began rehearsals recently for “Distance” the day after her final performance as another seriously screwed-up young woman in Paul Weitz’s “Roulette.” Interviewed on a recent morning, even after several cups of coffee Paquin stifled an occasional yawn. Playing misery is “emotionally exhausting,” she said, describing her profession as being all about “convincing an audience why they should care for these characters who are a disaster on the page.”

What can she say? “I’m just not drawn to happy, perky shows” – here comes that toothy, slightly shy grin again. “Maybe it’s a post- adolescent thing.”

Best supporting actress

Paquin is now twice the age of the 11-year-old New Zealand schoolgirl who won an Oscar for best supporting actress for her first professional acting role as the precocious Flora, cartwheeling on the beach in Jane Campion’s movie “The Piano.” Since entering Columbia University four years ago, she has been living on the Upper West Side, now with a pair of pooches that look “like Lady and the Tramp.”

“My class is graduating this spring,” she said a bit wistfully, having taken a “work break” during her sophomore year and never returned to college. “The Distance From Here” is her third Off- Broadway play and she also was in the well-reviewed London production of Kenneth Lonergan’s “This Is Our Youth” in 2002.

But the regret quotient seems minimal – except maybe the “small tragedy” of the cello she played as a child and has kept with her ever since. After a recent move to a new apartment, Paquin discovered that the instrument had cracked “right up the middle – which is really upsetting. I’d thought it would be one of those things that would be nice to go back to as a grown-up.”

Otherwise, she looks upon her life “as kind of a luxury. It’s this fantastic job I want to keep doing. Most of my friends are trying to figure out what they want to do. I know what I want to do.”

Before her stage debut in 2001′s “The Glory of Living,” Paquin made more than a dozen films, most famously the pair of “X-Men” movies in which she played Rogue, a lonely mutant with strange powers. She was last seen in Spike Lee’s 2003 movie “The 25th Hour” (promiscuous and precocious) and her next role probably will be in a film, she said.

A ‘disruptive’ time

Paquin’s parents, who are divorced, still teach in Wellington, New Zealand, where she grew up the youngest of three. In the ’90s, when she was establishing her film career, her mother lived with her in Los Angeles for several years. “It was such an odd, disruptive thing that happened to my life, I’ll be forever indebted to her for being supportive,” Paquin said.

“Part of me feels I’ve never left [New Zealand] because I’ve made a conscious effort not to lose touch,” she said, grousing that since “Lord of the Rings” was filmed there, it’s been increasingly difficult to book flights home. When she gets there, “it feels like I never left. So it’s sad when I have to leave.”

Asked what she might be doing if she hadn’t auditioned for “The Piano” when she was 9, Paquin mused that she probably would have left New Zealand anyway, “just not so soon.”

“I was so young when all that stuff happened, I can’t even remember what my interests were. Growing up in a small country out there in the South Pacific, I have no idea what I would have figured out for myself.”

She has never watched “The Piano.” “What’s the point? I’m not sure that small person would register in my brain as me.”