In Gemma Arterton's new film, The Escape, she plays a depressed woman who suddenly abandons her husband (co-star Dominic Cooper) and two young children. Heavily improvised, the film is intensely personal for Arterton, who collaborated closely with writer-director Dominic Savage and served as executive producer. As the film gears up for its UK release, we catch up with Gemma to discuss improvisation, working with children and carving her own career path.

How did the experience of improvising compare to working with a script?

When you're working with a script, sometimes that's the one thing that you're going to achieve, whereas if you're improvising you can just play around and maybe find five different ways of playing a scene. I think, as an actor, when you're improvising, you've just got to let go of any preconceptions and wanting it to work because you've got to fail, otherwise you're not going to get anywhere. I love that way of working, it's so liberating.

You co-created the film with Dominic Savage, and while not exactly autobiographical, it's still very personal to you...

Yeah, it's set in my hometown [Gravesend, Kent] where I was born and raised. We shot some of it in my Mum's house. And I guess there were certain aspects of it that were personal – it was a bit about my nan, who suffered from depression and committed suicide. It was also about my mum, who was miserable through her marriage and had a hard time raising kids. And then also about my life and about me escaping to Paris. I drew on a lot of stuff, whether I knew it or not.

What was it like working with the two young children?

It was really, really difficult shooting with the children in that house. That's where they live and they were too young to understand what we were doing, to the point where it actually became really difficult for me personally, because I knew it was stressful for them being around me. When I walked in the room, they were like, "oh no, it's that depressed, shouty woman". Usually, I'd mess around and play with them, but because I was playing the part I was playing, I just couldn't do that. That was quite tricky – it was hard for them and it was hard for their parents.

Was it important to keep the character sympathetic, given that she leaves her children?

One of the ways this story came about was I knew someone who'd been abandoned by their mother at the age of 14. I know a lot of people whose fathers have left them, but that's not frowned upon in the same way – women are supposed to have this connection with their children that's kind of atavistic, and yet some women just don't. And this was something that I just wanted to explore, because I don't think it's really talked about much. It's not something I want people to sympathise with, or go, "oh, I'm so glad she's not around her kids anymore", but I would love it to just create discussion.

A lot has changed in your career in the last few years – you've got your own production company, you've been making the films that you want to make...

I think my agent is like, "oh, remember that day when you were really famous?" And now, it's really great. I feel more creatively fulfilled than I've ever been. This is the way I like working, I like collaborating and I like working with writers, I love producing, I love the nitty-gritty of getting it together. I'm on the right path now. Before I was on somebody else's path, and now I'm on my one and it's so much better.

General release Fri 3 Aug