As much as the superstars love their fans, fans are predators." So said the late Dr Donna Rockwell, a clinical psychologist and one of the world's leading experts on fame and celebrity, during an interview with The Face in 2019. "In a way [fame is] almost like an excommunication because now you are an object. People are watching you."

Her words were an eerie foreshadowing of a sentiment recently expressed by Chappell Roan, the American singer who shot to stratospheric fame this year. "If you saw a random woman on the street, would you yell at her from your car window? Would you harass her in public?" Roan said in a social media video calling out fans' behaviour in August. "Would you stalk her family? Would you follow her around? Would you try to dissect her life and bully her online?"

In the raw, unfiltered post, Roan railed against such "weird" behaviour, calling it "creepy": "I don't care that this crazy type of behaviour comes along with the job, the career field I've chosen. That does not make it OK, that doesn't make it normal." The diatribe split opinion - some praised her for setting boundaries, others poured scorn for what they perceived as a rude and entitled outburst - and even garnered enough attention to be parodied in a Saturday Night Live sketch featuring Bowen Yang dressed as viral hippo Moo Deng. Since then, she's hit the headlines for telling off a photographer who "yelled" at her at both the VMAs and Olivia Rodrigo's GUTSWorld Tour film premiere, earning the nickname "Chappell Moan!" from some quarters. But her perceived temerity for daring to question the accepted "non-negotiables" of being in the public eye is shining a light on the, at times, distinctly unpalatable reality of being a celebrity.

Though her own trajectory from relatively under-the-radar artist to Gen Z superstar has been whiplash-inducingly fast, Roan is not the first to draw attention to the pitfalls of "parasocial" relationships. This term describes a one-sided connection with a celebrity or public figure - one in which the famous party is completely oblivious to the "connection".

Actor and singer Keke Palmer shared a troubling experience with a fan in 2022, whereby they started filming her against her wishes. "No means no, even when it doesn't pertain to sex," she tweeted.

Popstar Justin Bieber took the decision in 2016 to turn down photo requests from fans. "It has gotten to the point that people won't even say hi to me or recognise me as a human," he explained in an Instagram post. "I want to be able to keep my sanity." That same year, actor Jennifer Lawrence outlined why she had also started turning down selfies: "I think that people think that we already are friends because I am famous and they feel like they already know me - but I don't know them. I have to protect my bubble."

While the modern notion of celebrity is credited with having its earliest roots in the late 19th century, the internet and social media have fundamentally altered the nature of fame in the last decade or so. There has always been a darker side to the sparkle of hitting the big time - an issue that's poignantly explored in a forthcoming BBC documentary, Boybands Forever, on Nineties groups. The difference is that Roan and her ilk aren't retrospectively looking back and reflecting on the madness, but openly speaking about it in real time, while their star is still on the ascent.

The additional challenges of navigating celebrity in the digital age are also more apparent than ever: "fans" increasingly feeling like they have ownership over the object of their obsession; the mental health implications of overnight or overwhelming fame; the scrutiny and subsequent cancel culture inherent in reaching never-before-possible numbers of people via social media.

Dr David Giles, a reader in media psychology at the University of Winchester who's written extensively about fame in his two books, Illusions of Immortality and Twenty-First Century Celebrity, tells me that the landscape is changing due to media and technological change.

"One of the things I often talk about is the importance of the medium, and the affordances of that medium," he says. "Twitter/X affords something quite different from TV/radio. If you've grown up with social media and are used to negotiating lots of followers you can probably tolerate small increases in your fame, but suddenly having to deal with thousands of followers is a different matter. So even 'social media natives' can struggle with the increasing demands - you get used to a particular rhythm of communication and then it all changes, and you're getting different types of communication (abuse, etc) and you have to have a plan to deal with it."

Online abuse, he theorises, is often "opportunistic", because "people still can't quite believe they've got this level of access to celebrities." Think about it: in the past, a famous actor was distant, unattainable. You'd see them on the big screen, or gracing the pages of a magazine; the only way you'd experience any kind of interaction was by writing a letter to their "team" that they may or may not read, or queuing for hours at a film premiere in the vain hope of nabbing an autograph.

Dr David Giles, reader in media psychology

In 2024, the landscape has changed dramatically. If your preferred celeb has any kind of social media presence, you have access to far more of their lives, including intimate parts - maybe they've shared a video of themselves fooling around in their home, or pictures of their children. You can communicate with them directly via comments; they might even respond or retweet you. There's a greater sense than ever of knowing this person.

"If people have access to what feels like a private part of a celebrity's life, like their kitchen or their children or their garden or their hobbies, then they have a sense of familiarity with the celebrity," agrees Nicholas Rose, a psychotherapist who counts performers and high-profile individuals among his clients. "So they have a sense of a relationship, which won't be shared, it won't be being in a relationship. That causes confusion - they feel that they can just walk up to a celebrity and speak to them."

It's not the only aspect of contemporary celebrity that seems deeply unappealing. Traditionally, celebrities were protected from their public by several layers of gatekeepers depending on the industry - record companies, TV channels, managers, heavies - some of which could actually be viewed as a burden, stifling creativity. Now, social media allows users to cut through those layers and speak directly to fans - but this unfettered access has its shadow side. "Someone working in a traditional field like pop music doesn't really have the protection that the industry used to provide," says Giles. "Elvis could be smuggled out of the venue by his minders and safely deposited in a hotel, but today he would still be sharing his online space with his fans and whoever wants to insult him."

Unlike in the past, when a celebrity would know when they were "on" and when they were "off" duty, modern life also sees a huge blurring of the personal and professional spheres. "As we move to an online world it's harder to have those breaks between our internal and private life and our external and public life," adds Rose. "Doing celebrity is different from being celebrity; it's a bit like any job that you have to get into the mindset for. It's about that separation."

And separation is tricky when you're just out and about, living your life, yet get accosted at every turn - and roundly criticised if you don't feel like taking a picture with a stranger that day, as Dua Lipa found when she was on holiday with her family. (She was accused of being "rude" despite turning down the request, videoed and shared online, with commendable grace.) Not to mention getting pounced on backstage at Glastonbury and filmed while forced to listen to someone's cringe-making original song...

In a study entitled "Being a Celebrity: A Phenomenology of Fame", Rockwell and Giles identified four distinct psychological phases of fame that people go through: love/hate, addiction, acceptance and, finally, adaptation.

Roan is clearly in her love/hate phase (emphasis on the "hate") but after studying the lives of 15 US celebrities across a range of industries, Rockwell and Giles concluded that this usually moves onto "addiction". Celebrities start craving the attention they've become used to - "Behaviour is directed solely towards the goal of remaining famous," claims the study. Participants described the feeling as a "high"; one admitted: "I've been addicted to almost every substance known to man at one point or another, and the most addictive of them all is fame."

Next comes an acceptance phase, requiring the celebrity to get used to all aspects of fame, including those that are negative, "as the attention becomes overwhelming and expectations, temptations, mistrust, and familial concerns come to the fore".

Finally, there's adaptation. The person fundamentally changes their routines and behaviours to cope with the new normal, including - as in Bieber and Lawrence's cases - implementing strict boundaries when it comes to fans. "Once you're famous, you don't make eye contact or you keep walking... you just don't hear [people calling your name]," said one study participant.

It's not just a person's behaviour that changes with mega-stardom - their brain chemistry changes too. "The sad part of the adaptation is that if you are famous, your brain becomes accustomed to all of that attention, that adoration and all of those eyes on you," said Rockwell. Serotonin, endorphins and dopamine - the triumvirate of feel-good chemicals - can be released when we receive positive affirmation, such as hundreds of thousands of likes on social media, or fans chanting in adoration. "Your neurons get used to a certain level of excitation and stimulation. And then, forevermore, you kind of want it to be at that level."

Despite all of the above, there are clearly upsides. Otherwise, why would so many of us be bewitched by the idea of acquiring fame? And bewitched we are, right from childhood - a 2012 study found that "fame" was the biggest goal for children aged between 10 and 12 in the US, while, according to a 2019 survey of British children, "YouTuber" was the most desirable future occupation.

In her book The Psychology of Celebrity, social and behavioural sciences professor Gayle Stever asked several actors about the psychological impacts of fame. "They each felt that the fame they had gained was mostly positive in their own lives and mostly positive in the lives of those around them," she says. "I think most people are able to deal with at least the moderate levels of fame that are more common ... Perhaps the best answer is that fame is good until you get too much of a good thing."

It's this precise level of celebrity that can be tricky to navigate - not everyone is going to be Taylor Swift, sure, but fame is a fickle beast, something that may at first be courted but then cannot necessarily be controlled.

The impact this can have - as well as the pressure associated with having to stay at the top of your professional game to remain feted - can lead to a greater dependence on coping strategies, both healthy and unhealthy. Rose says a particularly effective tool for his celebrity clients is spiritual practices, whether organised religion, yoga or meditation. At the other end of the spectrum, though, is substance abuse: "There can be more reliance on alcohol, for example, or drugs."

It's a dark and devastating trajectory that has claimed a disproportionately high number of famous people's lives, from Heath Ledger and Amy Winehouse to, most recently, Liam Payne, who tragically fell to his death from a hotel balcony in Buenos Aires, aged just 31, while reportedly intoxicated. The former One Direction band member turned solo artist had spoken often about his struggles with fame and subsequent alcohol abuse, having suddenly been thrust into the role of a global superstar at the age of just 16. He called celebrity "a little bit toxic", and said of online trolling: "There's times where that level of loneliness and people getting into you every day every so often ... that's almost nearly killed me a couple of times." But stepping off the popstar treadmill was easier said than done: "Once you start, you can't really press the stop button," he once told The Guardian.

The media frenzy and endless speculation surrounding his death only lends credence to this assessment. As Little Mix singer Perrie Edwards put it: "There are no consequences for people's comments online. People are not looked after enough in this industry, people are put on a pedestal. They are treated like a god and then everyone jumps on this bandwagon of like 'let's tear them down'. But people are human."

It all paints a picture of fame as something to be avoided, rather than aspired towards; a state of being that's damaging, rather than desirable. Is the goal of achieving celebrity finally losing its lustre? That remains to be seen. But the fame game certainly seems to have become one where, the more you win, the more you lose.