Irish author John Boyne has opened up about the pain of his 11-year relationship breaking up and how he ended up in hospital after taking "too many pills", which he described as "a cry for help".

The Boy In The Striped Pyjamas novelist appeared on The Marian Finucane Show on RTÉ Radio 1 on Saturday to speak about his new book A Ladder to the Sky.

During the wide-ranging interview with presenter Brendan O'Connor, Boyne spoke to him about the breakdown of his marriage.

"I was in a relationship for eleven years, it ended two years ago and I guess the last two years while I've been writing this book I've thinking about my life and everything that led to that [the break-up]", he said.

"As time passes you start to analyse it more and more deeply.

"My husband was not somebody who was particularly interested in books, that's fine he doesn't have to be, he isn't obliged to be, so he wasn't into books or going to literary events.

"Moving forward, if I was to meet fortunate to meet somebody again the one prerequisite would be that they would have to be a reader, it's a big part of my life - I read and I write and I don't do much besides that."

The Dublin-born writer said the end of the marriage "wasn't something that I wanted to happen and I did everything in my power to keep it together".

He became emotional as he recalled how hard the break-up hit him.

"I didn't really see it coming, like any relationship there were ups and downs, good moments and bad moments, but in general I was under the impression that we were 99 per cent solid", Boyne explained.

"We had just come back from a fantastic trip to Australia... and it was only a few weeks after we got back that he said he didn't want to be in this relationship any longer.

"In truth I haven't handled this brilliantly over the last couple of years, if I'm honest.

"I have veered between great pain, great sadness, brutal fury at times, I ended up in hospital at one point."

When O'Connor asked him why he ended up in hospital, Boyne said it was from "taking too many pills".

"I haven't really talked about this before but it was one of those long, dark nights of the soul, everything really had just caught up with me. I knew my ex was seeing somebody else and there seemed to be no way back, I was absolutely distraught", he explained.

"I loved him, and I guess I still do, very deeply, I felt very worthless and very alone and nothing else like the books, just seemed to matter without him there beside me.

"It was probably not that serious in the sense that with everything I took, within half an hour I was phoning an ambulance so maybe subconsciously it was a cry for help. I ended up in hospital and it took a long time.

"I'm sure a lot of people will have had moments like that in their lives and you don't go through something like that without it changing you in some very deep way."

When asked by O'Connor how it changed him, Boyne replied: "It made me feel very worthless and I still kind of feel that way, because he wasn't there even when that happened, I felt that that entire 11 years had been a lie and a total sham.

"That every moment of 11 years where you give somebody love and then when the most terrible thing that can happen to you, where you're lying in a hospital bed and you call somebody and they're not there, and they're not coming.

"And maybe he was right not to come. I'm not going to lie, I've probably been a complete nightmare but if I was a nightmare it's because I married somebody who I wanted to spend the rest of my life with and I made promises about that and I fulfilled those promises and I expected them to be fulfilled in return to me."

The acclaimed writer said he is trying to see his ex's point of view and to move on with his life.

"I was probably a nightmare, I'm sure he has reasons, I'm not the easiest person to live with and I'm sure I'm a terrible monster at home most of the time", he said.

"I'm actively trying to move past anger towards acceptance and see something positive in the future.

"In fact those eleven years were filled with a lot of happiness with a really decent person who treated me very kindly through most of that time."

He added: "I guess I just miss him, I hope I don't across as sounding horrendous but I think it's just raw at the moment because the actual dissolution of the divorce is coming through in the next couple of weeks, so it's very much on my brain."

If you have been affected by any of the issues raised in this story you can contact Pieta House 24/7 Helpline 1800 247 247 or the Samaritans Helpline 116 123.