Lorna, this series is inspired by your book, Woman On The Verge Of A Nervous Breakdown. How did the TV version come about?

Sharon Horgan got in touch in about 2011 about the book, which she'd read, and we started chatting about adapting it, and we talked about maybe doing it as a film at one point.

Did you know Sharon at all, or was this out of the blue?

That was totally out of the blue. I didn't know her. She emailed me after reading the book, and we started chatting about how it would be interesting to have a conversation. It took quite a long time for anything to really happen, just because she also had a few pilots going on in the States and stuff like that. So, I tried writing it as a [one-off] drama, and it just wasn't really happening. I had a go, but it was really bad, and I did actually send it to Sharon which is quite embarrassing. I didn't know what I was doing to be honest!

Then we got down to doing it as a TV show, and we just back and forth-ed it a lot, and that was much better. Then in May last year, that was the first conversation I had about it with UKTV. So, although it was a long time ago since Sharon first got in touch with me, things seem to have happened very quickly since then.

Do you know why the book and the idea appealed to her so much?

You would probably need to ask her. What I do remember her saying in the first email was that she liked the fact it was very honest, but it was funny, and I think she liked the character. I think maybe also - we haven't really seen any in-depth portrayal of therapy on UK drama. I think actually that might have been one of our early conversations. It was like, "Are British audiences ready for therapy?" You know what I mean? So that was another conversation that we had. There was In Treatment, that American show. And there was Sopranos. Therapy was a big part of that. But I don't actually know if there has been a UK show where therapy is a big part of it. It's not that therapy's a massive part of this, but it is something.

It's the basis for the show...

Yes. And I don't think it's taboo exactly, and I think people talk about therapy and mental health issues much more than they did maybe even 10 years ago but seeing into that world has not been done on TV, maybe.

So, tell us a bit about how the TV show was adapted from the book.

Well, the book was very personal, and I don't know what I was thinking when I did that! Why I decided it would be a good idea to do that, I don't know. Whereas the series is different, it's evolved a lot from the book. I think having the other two female characters, who have got good stories, and interests, and are both relatable, helps to make it about the female experience. So that was a big part of the adaptation, rather than just making it about this one character who is a bit of a car crash.

Are you pleased with the casting?

Yes. I think the cast is amazing; really amazing. I had no say in it. It wasn't like I said, 'I want someone really attractive and gorgeous to play me!'. But of course, she is. When I watch Kerry, I don't think she's playing me, I don't see that at all. Possibly because I think I'm quite different now from what I was like back then and so there's that detachment.

But partly just because she really inhabits that character and has taken it on as her own. It's strange because it's the first time I've ever been on a TV set. I mean, when I'm watching it, I don't think, "Oh, my God. That's my life." I probably couldn't watch it if I did!

Did you and Sharon get on well?

We did. We're a similar age so we were both interested in these issues and these characters. I think there are some heavy, dark subjects but the common ground is we look at them with a comic sensibility. I think there is a shared comic sensibility to do with me being Scottish and her being Irish. I think those nations have a history of suffering but also the ability to laugh at dark things. I was in Glasgow and Edinburgh and she was in New York and London and LA. So, a lot of our conversations were on email, although we did talk on the phone and we did talk about some of our own experiences.

What are the characters like?

The Laura character is definitely who I was in my mid-30s: a woman who is a car crash and anxious and very insecure and a bit lost in life. She's basically self-destructive and very impulsive and in the series, we see her start to have therapy. She doesn't know how to be.

When I think about that now, a big part of that for me is because girls growing up were and are still conditioned to be nice and to be good and to put others first and to be people pleasers. I was a people pleaser and so is Laura.

In terms of the unsuitable relationship, and the job as a journalist, that was me. Where it's changed is setting it in Dublin and giving her a brother - I have a sister. It's me but then it takes on a life of its own. Then in terms of the other characters: Alison is 38 and decides she wants a baby. For women in their late 30s, if they do want kids and don't have a partner or the means or desire to do it by themselves, I think it's hard. I was that person. I was in my late 30s and wanted kids, which I did eventually have.

Then there's Katie who has met someone and had a kid, but it hasn't left her 'happy ever after'. I think that's the other thing that feels important to me. One of these three friends think a man is the route to 'happy ever after', another one thinks a baby is the route to 'happy ever after', and actually, neither of those things is the case.

I suppose I wanted to explore the fact that many women are bombarded with this romantic narrative which is the 'norm' - you meet someone, you get married, and you have kids. That's changing, and the next generation will have other ways to live which are more acceptable, but for my generation it still felt like if you weren't doing that, there must be something wrong with you.

What can we expect from the series?

Things go from bad to worse. Things unravel for Laura. She takes steps to make herself better, and her relationship with her therapist is the one relationship that could help her, but she does it for the wrong reasons. She goes to therapy because she wants to write about it and it's mainly a facade. She's not honest and she hardly scratches the surface of her layers of self-defence in therapy.

Alison realises that wanting to have a child isn't just as easy as getting back with an ex. And Katie - I really can't say anything at all about her without giving it away. It's really not what was planned but I really love the story we ended up doing.

Which was more similar to your experience?

It was in the early days, because therapy really challenges and disorientates you and forces you to fill the vacuum, the silence, and so much comes out in that. But it was not going to work, I don't think, for TV. So, she offers more observations. But she's frosty. She's so good. It's good fun because Laura's not entirely honest in therapy. So that's great fun when Sharon can play with that.

The female characters are witty and they're bright, and they're witty with each other. Was it important for you to portray female friendship that way?

Yes, it was important to us from early on that the women weren't stupid. Because sometimes, when you're writing funny, you can fall into that. So yes, it was definitely a conscious decision that these are smart women that you would hang about with. They've got good jobs, but they're making some bad choices.

Sharon plays your therapist. How does she play her?

She's funny, isn't she, as a therapist? My therapist, for a long time, said very little. And it's really hard to do that in a show, especially with someone like Sharon. You want her to speak. So, I think she's different in that she gives a bit more. You have to, for the drama. I mean, we did talk about her saying absolutely nothing, which would have been quite funny.

It's interesting to see women who are supportive of each other and competitive with each other at the same time.

Yes. I do think female friendship is so complex, and I think there are elements of sibling rivalry that come into female friendships.

I hope this comes across, but my honest experience of female friendships is that there is jealousy, and there is competitiveness, and there is sometimes not feeling great when your friend's life is going really, really well, and yours is going really, really shit.

It was quite important to me that was shown, and that they weren't just like, "Oh, I love you for being you," you know?

I know there's a conversation about not wanting to see women being bitchy or being competitive. But women are bitchy and competitive sometimes. I think to pretend otherwise is wrong.

Well, I've got great friends, but to pretend that there aren't elements of competitiveness I think is not true. I think that comes from when you're a kid, and if you have siblings, and you see it in a playground. It's part of the human condition.

You support your friends and you want the best for them, and you want them to be happy, but when your life is a car crash and it's not going well, which certainly [applies to] the Laura character, it's a wee bit harder for you to want your friends to be doing brilliantly. I think there are a few little lines in there that touch on that. I don't know how that'll go down, but...