Why did you chose to adapt this novel by Anne-Sophie Brasme, published when she was 17 years old? 
I discovered this book when I was still at school. I remember it really affecting me. Years later, I still remembered in detail this story of a dangerous friendship. So when I thought of making a second feature film, adapting this story seemed like the obvious next step. It was an absolute joy telling this story, which although isn't my own, certainly reminds me of a number of relationships I've had. We all meet in our lives someone that we find both fascinating and dangerous, who makes us feel weak, jealous and possessive. Like vampires, they suck out a part of ourselves, which can leave a mark on us. 

Breathe is your second film after The Adopted. Were you more confident this second time round? 
I hope I have made some progress since my first film. I felt very free. I wasn't in it and had more time for my team. However, I did feel more nervous and increasingly demanding. I don't feel frustrated as an actress, but I like filming actors and telling stories. The process of creation is fantastic.

How did you work with your two actresses, whose shoulders the film rests on? 
Joséphine and Lou are brilliantly truthful, beautiful and talented. They fully grasped this idea within three days of shooting. All I had to do after that was film them and love them. I wrote the film for them. They didn't necessarily meet the casting requirements for the parts, but for me it was obvious they were right. I knew that with a bit of work, we could make something great. But I didn't expect them to work so hard and be so powerful. I was very lucky!