Now, the founder of personalised greetings business Boomf said while there was no particular reason for his depression, he could recall feeling guilty for his privileged upbringing.
‘It’s what keeps you in bed, while anxiety makes you feel guilty for being there,” he told Tatler.
“I thought ‘What do I have to be depressed about?’ I’ve been so lucky with my upbringing, I had all the things I wanted.
“It’s not that I wanted more, but there was something that wasn’t always there... And the more I ignored it, the more it was taking over.”
While his parents, Carol and Michael Middleton, knew something “wasn’t right”, the 32-year-old said he felt incapable of talking to them about how he was feeling at the time.
The entrepreneur continued: “I shut myself off, I didn’t communicate with my family at all. But there’s only so long you can hold your breath.”
Following a period of therapy and time in Glen Affric – his brother-in-law James Matthews’ Scottish estate – Kate’s brother admitted to finally feeling content.
“I am happy – I feel like James Middleton again,” he said. “I feel like I was when I was 13, excited about life. I feel like myself again and I couldn’t ask for more.”
Elsewhere in the interview, Middleton – who is currently in a relationship with French financial expert Alizee Thevenet – spoke about the pressure of being in the public eye.
Following Kate’s wedding to the Duke of Cambridge in 2011, the then 23-year-old James said that the sudden media attention around him made him question his sense of self, his abilities and his business.
“Suddenly, and very publicly, I was being judged about whether I was a success of a failure,” he said.
“That does put pressure on you. Because in my mind I’m doing this irrespective of my family and events that have happened.”
On his relationship with the royals, he added: “I lead a separate life to them.
“If there’s interest in me, great. If there’s interest in me because of them, that’s different.”
In his January essay for the Daily Mail, Middleton described depression as “an absence of feelings” and revealed that his eldest sister’s work with mental health charity Heads Together was partly what inspired him to come forward with his own story of the condition.
“I know I’m richly blessed and live a privileged life. But it did not make me immune to depression,” he wrote.
“It is tricky to describe the condition. It is not merely sadness. It is an illness, a cancer of the mind.”
If you have been affected by any issues mentioned in this article, you can contact The Samaritans for free on 116 123 or any of the following mental health organisations:
The full interview can be seen in the August issue of Tatler, available on newsstands and digital download on Thursday 27 June 2019.