Prince Harry has revealed he "slipped into depression for about two weeks" after relocating to Canada in 2019.
The Duke of Sussex, who recently returned to the UK with his wife Meghan and their two children, said he experienced an "adrenaline crash" after moving to Canada to "get some space".
In a session with a neuroscientist for a video learning platform, Harry also described feeling "emotionally numb" following the death of his mother, Diana, Princess of Wales, when he was 12, and how he felt he had to "prove" he missed her.
After leaving the UK, the Sussexes lived on Vancouver Island, before they stepped back from royal duties in early 2020 and eventually moved to the US, where they have spent the last six years.
Harry said: "Being in Canada, away from the stressful environment where presumably my body was just pumped full of adrenaline, within two or three days, I experienced this adrenaline crash, something that I'd never experienced before.
"It was as if I needed stress in order to get the adrenaline to make my brain function because I became useless around the house.
"I actually slipped into depression for about two weeks and I felt like I couldn't function without adrenaline."
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A 'student of grief'
Speaking about the death of Diana, Harry described himself as a "student of grief" and said he had tried to "outrun" his feelings.
"I'd spent so long emotionally numb, to a large extent, because I felt disloyal and guilty for the possibility of being happy and joyful without her," he said.
"I felt like I had to be sad and I had to be emotionally numb in order to prove to her that I missed her."
Harry also revealed he had forgotten his mother's laugh, and that a therapist suggested spraying her perfume, which helped him to "unlock everything that had been locked previously".
He added: "The reality is, what I discovered was actually she just wanted me to be happy."
(c) Sky News 2026: Prince Harry opens up about 'depression' after leaving UK - and describes
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