“Get Ready, it’s about to get a little bumpy.”

That was the first sentence of a letter Liam Payne wrote to his 10-year-old self, which he read out on BBC radio in 2020.

“You’ll have the most amazing time of your life, travel the world and live a life you barely imagined,” he said.

“Then it will end for a while, and you will be left with nothing but the steering wheel. It will feel scary, like you’re alone, but you are not.”

The pop sensation died on Wednesday aged 31 after a fall from a hotel balcony in Argentina. The exact circumstances around his death, or what happened in the final weeks of his life, remain unknown.

But the star, who shot to global fame as a 16-year-old member of One Direction, had spoken for years about his struggles with mental health – and the challenges of adapting to stardom.

Runners-up on the 2010 series of The X Factor, One Direction were a new, different-style of boy band – approachable, relatable, and, apart from their musical talents, normal.

They were the boys-next-door, whose age and good looks made them heartthrobs to millions of young fans around the world.

They went on to sell more than 70 million albums, complete five world tours, produce a feature film and star in a charity music video alongside then-prime minister David Cameron.

All that – at an age when many young people are worrying about their exams, their first loves, or getting tickets to their next gig – let alone starring in it.

“I mean, it was fun,” Payne would later reflect in an interview with Men’s Health Magazine. “We had an absolute blast, but there were certain parts of it where it just got a little bit toxic.”

Paparazzi photographers. Tabloid newspapers. Night after night in hotel rooms, separated from family. Blacked-out tour buses. Fans screaming for autographs. And the new and rapidly growing world of social media.

Few, he felt, could understand the intense pressures of stardom at such a tender age.

‘It’s almost like putting the Disney costume on before you step up on stage,” he said.

He also admitted he used alcohol to cope “because there was no other way to get your head around what was going on”.

By the time One Direction split in 2016, global fame was all the then 22-year-old Payne had known as an adult.

“It can be quite difficult to give up expectations of being a megastar,” says Prof John Oates, who was involved in the British Psychological Society’s consultations with the government on child performers and the duty of care for adult contributors.

“Being in a boy band ceases to become so possible when you’re no longer a boy. So there’s a need to become, in a sense, a different sort of famous person. So that’s a new challenge.”

Payne’s bandmate Harry Styles seemed more suited for that challenge.

His androgynous looks were more in harmony with the direction the music industry was progressing in 2016. He also began acting, featuring in Hollywood blockbuster Dunkirk the following year.

Payne, however, struggled to make the transition.

In 2019, he released a solo debut album, LP1. Eight tracks of R&B, it did not capture the One Direction fan base, and failed to take off.

The struggles of teenage stars have long been a topic of public discussion, from Britney Spears to Justin Bieber.

Reality TV stars have faced similar challenges, with both Love Island host Caroline Flack and contestant Mike Thalassitis tragically taking their own lives in recent years.

Speaking on the Diary of a CEO podcast in 2021, Liam Payne said of his own struggles: “I was worried how far my rock bottom was going to be. Where’s rock bottom for me? And you would never have seen it. I’m very good at hiding it. No-one would ever have seen it.”

A key challenge for young stars, according to Prof Oates, is managing the comedown after a long period of fame.

“If fame has been so important to them for their self-esteem, how can they be helped to manage the loss of that?” he asks.

“An important move in personal development is moving from external sources of self-esteem to internal sources. Part of this is to do with something called reflective functioning, that you’re able to reflect on yourself as a person and you may become less reliant on others for your sense of self.”

For those who have entered adulthood as a star, that process can be especially difficult, he says.

Shortly after Payne’s death, fellow 2010 The X Factor contestant Rebecca Ferguson wrote a tribute: “We both met at Euston station and shared the taxi together to X Factor. I can’t help but think of that boy who was hopeful and looking forward to his bright future ahead.

“If he hadn’t jumped on that train and jumped in that taxi I believe he would be alive today.”

Former X Factor judge Sharon Osbourne said: “We all let you down.”

“You were just a kid when you entered one of the toughest industries in the world. Who was in your corner?”

If you have been affected by this story the BBC Action Line web page features a list of organisations which are ready to provide support and advice.