The Prince of Wales feared his brother was being “brainwashed” by his therapist, the Duke of Sussex claims in his memoir.
Prince Harry reveals that he was almost overcome by emotion as he gave a speech at the WellChild Awards in October 2019.
He choked up, he writes in his book, Spare, and was briefly unable to speak.
Prince William, who was on a royal tour of Pakistan at the time, texted him some time afterwards to express his concern, noting that he was clearly struggling and needed help.
The Duke says he reminded his brother that he was doing therapy.
“In fact, not that long ago he’d asked if he could come with me to a session because he suspected that I was being ‘brainwashed’,” he writes.
“‘Well come’, I had responded. ‘I’m sure it’ll be good for the both of us’.
“He never came. His strategy was obvious: I wasn’t well, which meant I wasn’t in my right mind, and that’s why I was behaving questionably.”
The Duke reveals that he had to “work hard” to keep his texts to his brother civil.
But the conversation descended into a three-day argument, all day and all night, the likes of which they had never previously endured.
He claims that after months of therapy his “worst nightmare” was coming to fruition – that they were becoming strangers.
“He could no longer recognise me, tolerate me,” he writes.
Harry admits that he saved all of the texts and still reads them sometimes, with sadness and confusion, wondering “How did we ever get there?”
However, he reveals that towards the end of the row, Prince William wrote that he loved him and that they would do anything necessary to help him.
“He told me to never feel any other way,” he says.
The Duke has continued to be a strong advocate of therapy and thanks more than a dozen practitioners in the acknowledgements of his memoir.
They include John Amaral, a California-based “energy practitioner” who says he can help “heal” depression and post-traumatic stress and Eric Goodman, the creator of Foundation Training, a yoga-like series of exercises designed to deal with chronic back pain.
He also thanks a Pilates coach and an acupuncturist who specialises in helping women struggling with fertility problems and pregnancy.
However, he opted not to name the UK-based therapist whom he credits with “helping unravel years of unresolved trauma.”