Charles Spencer reveals he went to a 'residential treatment' centre last year  after having a 'breakdown' when he revisited horrific childhood abuse in his memoir A very Private School

Princess Diana's brother Charles Spencer has revealed he had to seek mental health treatment after suffering a breakdown when writing his deeply emotive memoir.

Earl Spencer, 59, appeared on Sunday with Laura Kuenssberg on BBC One this morning where he revealed he unlocked years of trauma in writing the book.

The memoir, A Very Private School, reveals horrific details about the physical and sexual abuse Spencer suffered during his childhood, while he was educated at Maidwell Hall boarding school in Northamptonshire the 1970s.

In the book, which was published this week, Earl Spencer exposed in devastating detail the sexual assaults and beatings he experienced at school.

Speaking to the BBC journalist, Spencer revealed that after writing the book, he sought help at a 'residential treatment centre' last year due to the 'trauma' that resurfaced during the writing process which caused a 'breakdown'.

Speaking on the BBC's Sunday with Laura Kuenssberg, Charles Spencer revealed he had to seek help at a 'residential treatment centre' after finishing his memoir last year

'Confronting... evil is a very, well, it's cataclysmic really,' he explained, referring to the cruelty he suffered as a child.

'I've always been intrigued by what humans are capable of doing for each other.'

When asked how 'putting pen to paper' and detailing his experiences had affected him, Spencer revealed he was taken to 'a very dark place'.

He explained: 'I had endless nightmares' and revealed he was equally traumatised by the 'appalling things' that had happened to his friends at school, which resurfaced when he interviewed them. 

The uncle of Prince Harry and Prince William also revealed he has not had an alcoholic drink 'for many weeks' as he becomes more 'grounded', and spoke about undergoing EMDR therapy.

EMDR stands for eye movement desensitisation and reprocessing, which is a form of therapy that has been shown to reduce the effects of post-traumatic stress disorder. 

Earl Spencer (pictured with his sister Princess Diana), has revealed in horrific detail how he was physically and sexually abused in childhood

Earl Spencer explained that he did not feel suicidal after writing the book, but began to question 'what's the point' in things as he revisited such horrific trauma. 

Elsewhere in the interview he also revealed that his older sisters had been piled with laxatives as a punishment from a nanny. 

'A different nanny was punishing them by ladling laxatives down them, and my parents couldn't work out why they were constantly ill,' he said.

The Earl made it clear that he did not blame his parents: 'They did their best, like 98 per cent of parents do', and lamented that they 'did not know.'

In the book, which was published on 14 March, Charles reveals how he was molested by a female assistant matron at the age of 11 at the Northamptonshire prep school.

Describing his abuser as a 'voracious paedophile', Charles claims she preyed on him and other young boys, grooming and then abusing them in their dormitory beds at night. The prep school has now reported itself to the council following Earl Spencer's claims.

During his interview with the psychotherapist, Charles said the school 'sewed demons into the linings of the souls' of the abuse victims, which made them feel like 'they were responsible' for what had happened.

The Earl explained how he was only able to process the trauma when he tried a new form of therapy called the Hoffman process - which aims to resolve negative behavioural patterns.

Earl Spencer's memoir, A Very Private School, which was published this week, reveals how he was abused at boarding school

He explained: 'The penny dropped for me in my early 40s when I went to do a thing called the Hoffman process, which is really looking at your childhood and letting go of your childhood.

'And I mentioned my years at Maidwell as a sort of sideshow actually, to the therapist who was in charge of me.'

During the session, the therapist asked Charles to tell him one thing he'd never confided in anyone before.

Diana's brother continued: 'I told him I'd been sexually abused as a child and then we got into the whole subject of Maidwell.'

Later on in the session, the therapist told Earl Spencer that the way he described the Maidwell headmaster made him believe that he had seen him as a 'surrogate father'.

Maidwell Hall in Northamptonshire said the allegations were difficult to read about and a referral had been made to the Local Authority Designated Officer.

They said: 'It is sobering to read about the experiences Charles Spencer and some of his fellow alumni had at the school, and we are sorry that was their experience.

'It is difficult to read about practices which were, sadly, sometimes believed to be normal and acceptable at that time. Within education today, almost every facet of school life has evolved significantly since the 1970s. At the heart of the changes is the safeguarding of children, and promotion of their welfare.'