Olivia Colman is back for a second series of Flowers...

How would you describe Flowers to someone who had never seen it? It's a difficult show to classify.

I'd say it's a dark comedy, but some funny things come from the darkest places, and Will [creator Will Sharpe] does that with aplomb.

Something really tragic happens, and then he pulls the rug out from under your feet and makes you laugh, something stupid happens. As you say, it's really hard to classify. But essentially, it is a comedy, and it is very dark.

There's really nothing like it, is there?

No, absolutely. The first series starts with a scene of someone tying a rope round a tree, a suicide attempt, and it's a comedy! A lot of people would just think "That doesn't sound right!" So there really is nothing else like it.

What was it that initially attracted you to the role of Deborah?

I think it was a mixture of liking the role, but also of just really liking the whole thing, and wanting to be part of it. It was because it was different. I find that interesting. I find comedy interesting, and I especially find it interesting when it's different, like Will's comedy.

Where do we find Deborah at the start of the second series?

She and Maurice have gone away together, in a caravan, trying to make things work. She loves him, but it's not really working. And she's writing a book about Maurice's depression, and she's really enjoying it.

Is that part of her problem - she can see they're all struggling, and she is so desperate to help them?

Yes, certainly in the first series she doesn't know how to help them, so she just tries to be as buoyant as possible, to keep everyone up with her. And that's not the way. And then I think as the second series progresses, she realises she has to listen and try and help in a different way. But she has to stay strong for everyone else. They can't all fall apart.

You've talked before, at the Mind Media Awards, about the media's responsibility to accurately represent mental illness. I imagine, then, that this is a subject close to your heart?

I think we all know someone who's struggling or has struggled. I think anything that's genuinely affecting people should be dealt with responsibly. I'm proud to be part of something that tackles something head on, warts-and-all, but does it sensitively. If the script wasn't the script that Will had written, I'm not sure I'd be able to cope with it, but he's done it so beautifully that he's doing it responsibly, and doing it really well.

We're making it all sound incredibly depressing - does the series still have the ability to make us laugh as well as cry?

Oh God, it's hilarious. It's impossible to try and explain how well it achieves that balance.

Do you like shows that mix the tragic and the comic?

Yes, I think it makes the funny bits funnier. You're so desperate for that release. It really, really works in this.

The show is very much the creation of Will, who writes, directs and stars in it. What's he like to work with?

I love Will. I think he's totally amazing, He's a proper genius, and such a nice man. And he's incredibly embarrassed if anyone says anything nice about his ability. And his notes are some of the best director's notes I've ever been given. He's insightful, he's really genuinely effing marvellous. And he's about 12. That's irritating, but once you get over that fact, then you can just accept that he's great. I'll get over the fact that I could be his mum.