He’s a Doctor. He’s an Actor. He’s an Indie Heartthrob.

Actors have a long history of indulging in side projects: Some use their off time to write books, while others even front rock bands. But it’s fair to say that few thespians navigate a dual career quite like Anders Danielsen Lie, who currently stars as a lingering love interest in both “Bergman Island” and “The Worst Person in the World” — an indie-film doubleheader that prompted one critic to dub him “the art house’s next great ex-boyfriend” — while still working full-time as a doctor in Oslo.

“It’s been overwhelming,” Lie, 43, told me over a recent video chat, and he wasn’t kidding: In early January, he was named best supporting actor by the National Society of Film Critics even as he worked three days a week at a vaccination center in Oslo and two days a week as a general practitioner. “It feels kind of abstract because as an actor, the most important part of making a movie is the shoot itself,” he said. “Then, when the film is coming out, it’s kind of a surreal experience.”

Expect things to get even more surreal as the acclaimed “The Worst Person in the World” finally makes its way into American theaters on Feb. 4. In this romantic dramedy from the director Joachim Trier, Renate Reinsve — who won the best-actress prize for the role at the Cannes Film Festival — stars as Julie, a young 20-something trying to figure out her future. For some time, she takes up with Lie’s character, Aksel, an older, charismatic comic-book artist, and adopts his settled life as her own. But even when they break up and Julie discovers new pursuits, she finds her bond with the cocksure Aksel hard to shake.

Lie previously collaborated with Trier on the well-reviewed films “Reprise” (2008) and “Oslo, August 31” (2012), but “The Worst Person in the World” has proved to be something of a breakthrough: Already, the internet has crafted video tributes to his character, and the film has struck a chord with audiences who prefer simple, human stakes to superhuman ones. “It felt like we made a very local thing from Oslo, and we were afraid if anybody else in the world would understand,” Lie said. “But people on the other side of the planet can identify with it. That’s what is so nice about feature films, they kind of bring people together.”

Here are edited excerpts from our conversation.

With Aksel and Julie, it feels like the qualities that drew them to each other eventually drive them apart. How would you sum up their relationship?

He’s good at articulating her emotions and thoughts, and that’s something she probably wanted at an earlier stage in their relationship, but at this point, she’s just annoyed by it. He’s a pretty kind person, but he is also, in a subtle way, trying to dominate her by using language as his tool, because that’s what he’s good at.

Is Aksel a “bad boyfriend,” as a recent Vanity Fair article asserted?

I don’t see him as a bad boyfriend at all, actually. She’s not bad; he’s not bad; they’re just human. They are put in situations where they have to make hard choices and end up feeling like the worst people in the world, but it’s not really their fault. It’s life’s fault, in a way.

In the film, we watch Julie swipe between different identities, trying on new jobs, new passions. Did you act the same way at that age?

I personally thought that my 20s and 30s were hard, tough years, because I spent so much time trying to figure out who I was and what to do. I still haven’t made that choice, but that doesn’t bother me so much anymore. I’m happy enough to have two kids and a wife. Maybe it’s as simple as that.

When you were younger, did you feel pressure to make an ultimate choice between acting and medicine?

This has been my ongoing identity crisis.

Maybe that’s just the bifurcated life you feel most suited to.

It’s definitely a bifurcated life, and sometimes it feels like an identity crisis because it’s just a lot of hustle making the calendar work out. It’s hard to combine those two occupations, and sometimes I also wonder a little bit who I am. I’m trying to think that I’m something deeper than that: I’m not the doctor or the actor, I’m someone else, and these are just roles that I go into.

Your mother is an actress. Did that affect the way you regard an actor’s life?

My mother is not the typical actress — she’s not a diva or anything like that. She’s a very ordinary person, and I think it’s important to have a foot in reality if you want to portray people onscreen with confidence and credibility. But I’ve grown up seeing how it is to be an actress and how it is to be a doctor, and ended up being both! I probably should go into psychoanalysis or something.

Your father was a doctor. That pretty much split you right down the middle, doesn’t it?

Exactly. Maybe it’s an inheritable disease.

Does one career inform the other?

Working as an actor has improved my communication skills as a doctor because acting is so much about listening to the other actors and trying to establish good communication, often with people that you don’t know very well, and that reminds me a little bit of working as a doctor. I meet people, often for the first time, and they present a very private problem to me, and I have to get the right information to help them. It’s a very delicate, hard communication job, actually.

You made your film debut when you were 11 in a film called “Herman.” How did that come about?

My mother had worked with the director, so she knew he was searching for a boy my age, and she asked if I was interested in doing an audition. I didn’t really know what I had signed up for — I was 10 years old, and it felt like just a game that we were playing. I remember when the director wanted me to do the part, he came to our house with flowers and said, “Congratulations,” and I was frightened because I realized, “Now I really have to play that role and deliver.” For the first time, I felt this anxiety of not doing a good job, the exact same feeling I can get now in front of a shoot that really matters to me. I can be scared of not rising to the occasion.

After that film, you didn’t work again as an actor for 16 years.

“Herman” was an overwhelming experience. I felt like I was playing with explosives. I was dealing with emotions and manipulating my psyche in a way that was kind of frightening.

Do you think that sense of being overwhelmed by it as a child may inform your decision to lead this bifurcated life? Acting can never completely overwhelm you now because you also have an entirely different career going on at the same time.

You should be an analyst. I think you’re onto something here because I’ve always felt that it wouldn’t be good for me to work full time as an actor, especially when the parts are really dark and emotional. I’ve often thought that I have to find a psychologically sustainable way of working as an actor. I don’t know if I’m there yet, but I’m starting to see how I can protect myself.

It’s interesting that you rejected it for so long, until Joachim Trier asked you to audition for “Reprise.” Had that not happened, do you think you ever would have returned to acting?

When I was asked to audition for Joachim’s first film, I had no plans of doing any acting — I had one year left in med school and had other plans. But I have, many times, asked myself why I keep doing this, because I’m very neurotic as a person and if I perform onstage I get very, very nervous. It costs me a lot to do this, and I often ask, “Why do you do it if it’s so hard?”

So why do you?

I think the process of creating a fiction and the transgressive experience of entering that fictional character is something that fascinates me. It’s like you are discovering and amplifying potentials in yourself that you’re probably not able to explore in real life.

Have you ever done that “come out to L.A., meet the Hollywood people” thing, or do you still keep all that at arm’s length?

I’ve been to L.A. many times, but I don’t have naïve illusions about what it is like to be a film actor. It’s important for me to be in this industry for the right reasons. I definitely have ambitions, but I hope they are more artistic ambitions and not career ambitions.

I think those are good ambitions to have. I’ve seen European actors who have a big moment like yours, and they cash in quickly to play the bad guy in an American comic-book movie.

Maybe it would be great fun to play that character! But I try to have a long perspective. I want to work with this for a long time, and I don’t want to be someone who pops up one year and then you never hear about that actor again. I want to build a career over time.

After everything that’s happened this past year, have you felt more drawn to acting or medicine?

In an ideal world, I would like to continue doing both. During the last five years or so, I think I’ve managed to find a balance that is meaningful and that doesn’t exhaust me too much. But I don’t know. I keep postponing that final choice.

If there hasn’t been a final choice by now, maybe there will never be one.

You may be right. We’ll see.