From The Hour and The Iron lady to Suffragette and River: Abi Morgan's remarkable career

The idea behind River came from two places – Morgan’s complicated love affair with London and her interest in mental health. “I love London, it’s so exciting and I love bringing up my children here. But London also kills you – it’s exhausting, it’s relentless; it demands a lot, financially, emotionally, physically – and sometimes when I come back to London I feel like a sponge absorbing all these feelings of how hard it is here.”

She is a great admirer of Stephen Fry and Ruby Wax for their courage in speaking up about their own mental health problems to highlight why society needs to step up and acknowledge that mental wellbeing is as important as physical health.

This trailer contains some spoilers

“I felt that writing this was a way to explore my own mental health. I talk to myself all the time [as River does] – it’s something my children have observed in the car. I’ll often have the argument with the person that I really want to say to their face.

“Occasionally, I’ve been on the tube and I’ve been thinking about something, and I’ll see someone looking at me, and I’ll think, ‘God! I’m talking out loud.’ And I realise that from anyone else’s perspective, I must look mad.

“I wanted to say, ‘In police departments, in hospitals, in newsrooms, in the banking industry, we have people who are dealing with emotional situations that fracture their minds and so that’s what made me start to write this.'”

The north-London house she shares with her family (her partner, actor Jacob Krichefski, and their children, Jesse, 14, and, Mabel, 11) looks stunning in the photographs she shows me – lots of white with splashes of colour, an internal swing for the kids, polished concrete floors and a chic kitchen.

All of this is a far cry from her own upbringing. In the past Morgan has talked freely about her devastation, as a teenager, when her parents broke A up and the difficulties her mother had bringing up three children in a small flat with no furniture. For many years she had no contact with her father, actor-turned-director Gareth Morgan – although they had reconciled before his death. But now, Morgan is more circumspect; aware that revisiting this time, so publicly, can be hurtful to others.

“My parents’ divorce was very difficult. Divorce is essentially incredibly painful, but it’s also an essential part of life. The most important part of life is that you find a way to be happy and to live as honestly as you can – and in order to do that, our choices change.

“I think there are good divorces – I’m just starting to research a series about divorce and I’m writing about divorce lawyers and it’s fascinating. My parents did the best they could at that time and so I think it would be naive to think that divorce is wrong and terrible. For many people, there are good divorces and it’s the right thing to do. But it’s still inherently sad.

“And I have to be careful. I’m a very privileged middle-class woman. I have two great kids and a very successful career and I think you can end up seeming... well, I don’t deny my background, but there’s a lot of storytelling about it, to a certain degree.

“Yes, I did move around a lot and, yes, I was brought up by my mother and, yes, it was hard in many ways. But what came out of that was something very rich and I have an amazingly close relationship with my mother, and I have very strong bonds with my brother and sister. And I’m here and I feel very lucky about that.”

River begins on BBC1 tonight (Tuesday 13th October) at 9.00pm