The Duke of Sussex has partly been so open about the royal family’s secrets in his memoir, Spare, because he is “hurting”, according to a trauma recovery expert.

The autobiography, published on Tuesday, contains allegations including that his brother, the Prince of Wales, physically attacked him, and that Meghan upset the Princess of Wales by saying she must have “baby brain” in the run-up to the Sussexes’ 2018 wedding.

Dr Lisa Turner, trauma recovery expert and founder of CETfreedom, told the PA news agency Harry’s motivations could stem from “trauma”.

She said: “There is this sense that he really does want to let his family know he’s hurting.

“Hurt people, hurt others. They do it completely unintentionally, because their hurt is so present, they can’t perceive anyone else’s hurt.

“All behaviour has a positive intention – he’s trying to get something, whether it’s catharsis, whether it’s a reaction or response.

“It’s not an immediately obvious behaviour pattern, but when people attack, criticise or accuse another of doing something, it’s actually a sign of love.

“They want acknowledgement, recognition – they’re all forms of love.”

Dr Turner said the publication of Spare had not come at the “ideal time” given its closeness to the King’s coronation in May and the Queen’s death last year.

She said there is “grief in the family and he’s choosing this moment to bring attention to himself at a time when a more empathetic, sympathetic and sensitive person” might pause.

There is this sense that he really does want to let his family know he's hurting

Dr Turner has not met Harry and said her comments were “entirely speculative, based on two decades of working with people who’ve had various sorts of trauma”.

“A definition of trauma is when we have an event, or a series of events in the past, which have caused our neurology to change in a way that is maladaptive,” she added.

“(This means) it no longer enables the individual to easily get the results they want.

“We all have fundamental needs that ideally we get met in ways that are healthy.”

Dr Turner said Harry’s behaviour around the publication of Spare “is an attempt to get some kind of need met”.

She added: “I don’t know that (writing the book) is actually meeting that need.”

Spare is set to become one of the biggest books of the year and one of the best-selling pre-order titles of the past decade, according to industry experts.