I wait for Cat Marnell to stop playing Cat Marnell. She doesn’t

How To Murder Your Life

Author: Cat Marnell

ISBN-13: 978-0091957353

Publisher: Ebury Press

Guideline Price: £14.99

For the majority of How To Murder Your Life, the list of things Cat Marnell doesn't care about is long and varied: her health, her relationships, jobs, three-day hangovers, the concept of time, jobs, sleep, the world economy, intimacy, deadlines, getting dressed for day-time, jobs, getting dressed for night-time, boardrooms, production meetings, apartments, friends, sentence structure and most troublingly – staying alive.

It’s 2009 and, by day, Marnell, a beauty editor with ambitions as lightweight and transparent as an American Apparel T-shirt, has full swipe-card access to fashion dictatorship, Condé Nast. “I’m not a failure,” she says brightly, “I work at Condé Nast!” Unfortunately, by night, she’s a serious addict, enslaved to cocaine, alcohol, amphetamines and, by the evidence available here, the exclamation mark. Driven by self-loathing and tortured by eating disorders, Marnell’s intent on destroying herself and as she unabashedly tells us – she’s not paying for any of it.

After losing her job at Lucky magazine, two rehab stays and one stint in a psychiatric hospital, Marnell rose to prominence by writing shameless beauty advice for "party girls". In the generally clean-cut and anodyne world of beauty columns, her dangerous, and darkly witty, advice was a breath of stale air. She stood out in a culture that practically demands female subservience. Her sharp sense of humour, physical attractiveness and ability to snort massive amounts of substances propelled her easily on to Page Six and beyond. If this doesn't sound like a new story, it's because it's not new – and Marnell knows this. You get the sense throughout, despite her faux-protestations and wide-eyed surprise, Marnell understands exactly how celebrity works. Her favourite hobby is collaging, ripping out famous images and re-assembling them on her bedroom walls; she claims to have read Edie Sedgwick's biography more than 200 times. She describes her own sectioning as "very Girl Interrupted". It's a short walk from glamorous illusion to functional delusion.

In How To Murder Your Life, it's impossible to separate reality from fantasy, from complete madness to self-mythologising genius. In a candid interview with the Telegraph, Marnell admits to being studied, to not being born with "a fur coat and eyeliner", but there is no trace of that honesty here. Even her own authenticity is a sham. Is she revealing her true self or, just like a reality star, presenting herself at her worst moments for our entertainment? The genuine tragedy of her teenage years, particularly her relationship with her father, is abandoned in favour of shallower, but louder, revelations about bad sex and angel-dust trips. The result is maximum revelation with minimum depth. I was waiting for the moment Cat Marnell stops playing Cat Marnell. It never comes. Like any addict she wants the lie, but the lie is temporary and thin.

If the gulf between the real and pretend is unbridgeable, so is the gap between Marnell and the women she idolises. Sedgwick had Warhol, Courtney had Kurt – both worshipped, rightly or wrongly, for their enduring legacies. Marnell has someone, hilariously, called Same, a brief sighting of Chris Brown and a weekend pass to Art Basel. She’s striving for cool-girl status in terminally uncool places.

When celebrity isn’t the drug and currency – there are actual drugs and currency. If a credit card could speak, I imagine it would sound like this book. It costs a lot of money to look cheap, and it costs even more to constantly fall apart. Marnell is cushioned by her parents, colleagues and forgiving relatives. Her luck and privilege barely needs mentioning. Still, if you are to hate her for the twin crimes of being both beautiful and wealthy, save some ire for the companies who capitalised on her wild image, did little to help her and, more than likely, cashed cheques as she lay comatose in her filthy apartment. Female self-immolation has always been big business.

The problem is what Marnell thinks makes her interesting – style, money, drugs – isn't why she is interesting. What truly makes her remarkable is her ability to move effortlessly between worlds. You get the impression she is just as comfortable in a room full of models as a group of "weirdos" in a rehab facility on the outskirts of New Jersey. She treats everyone equally – a rare gift. Her difficult upbringing has made her highly attuned to other people's pain and she proves she is capable of finding warmth and friendship in even the most extreme circumstances. This skill suggests, if she could only turn off the front-facing camera, take herself out of the frame for even a second, she might be capable of capturing a moment free of solipsism and artifice. How To Murder Your Life is disappointing not because Marnell is shallow (she is) and spoilt (she is) but because – like the shadowy and abusive men who haunt these pages – you know she can do much better.