I did a 10-page treatment, then started working on biographies for each of the characters. By the time I was finished writing those biographies, I understood completely where each of those characters was going.

I'm finding that people enjoy the film no matter their age. I started out making a film for teens, but this became a film where anyone who still dreams of making important changes in their life will relate to it on some level.

To make things even more challenging for ourselves, we decided to use only available light. As difficult as it was, we wanted to keep the look as real as possible.

I decided to use black-and-white for the film, because that is the image of adolescence to me. We see teen films all the time where the colors are very bright and always changing. But teens tend to look at things in very specific terms. They believe in things one way or the other, and they see themselves and the people around them one way or the other.

I started out with an idea that was really kind of silly. I liked the idea of four people sitting in an apartment with nothing to do on a Sunday morning. That doesn't sound very exciting. The challenge for me was to make it as involving as possible.

By the time the treatment is given to our patients in a clinical trial, it has been studied for many, many months, even years.