“Tracey Emin: 20 Years”, at the Scottish National Gallery of Modern Art, is a retrospective in the form of a labyrinth of blurted confessions. The visitor who penetrates to the centre of the autobiographical maze will find there, in all its melancholy bathos, the artist’s signature work: My Bed, of 1998. The celebrated unmade bed is a rebarbative memento of low-rent, self-destructive excess, the classic instance of Emin’s particular variant of abject expressionism. An island composed of grey rumpled sheets, dribble-stained pillows and a crushed mess of duvet is bordered by the flotsam and jetsam of squalid debauchery: an empty bottle of Absolut vodka, a half-squeezed tube of KY jelly, some condom wrappers, a brimming ashtray, a crushed duty-free size carton of cigarettes and a knot of knickers and tights, still entangled in the twist of sudden undress.

 
It is a work of art that resembles the scene of a crime, or a suicide. When she first exhibited it, the artist hung a noose nearby, a touch of melodrama subsequently deemed superfluous, although one that had its roots in Emin’s genuine belief that she was killing herself with drink at the time. But My Bed might equally well have been inspired by the memory of an Endemol camera panning over some bedroom debris in the Big Brother house (no one was a bigger fan of Big Brother, in the early days of the franchise, than Tracey Emin); and it also bears a distant, belated family resemblance to certain types of Old Master painting – being, in effect, a Dutch vanitas still life constructed as a tableau vivant from the materials of a modern bedsit. The combination of associations might be unusual but it is also a reasonable guide to Emin’s nature as an artist. She is fond of borrowing from the traditions of high art, both old and modern. She feeds voraciously on her own life. She seems so blatantly compelled to make an exhibition of herself that her art might be said to aspire to the condition of a reality television show – albeit edited in such a way that the focus is only ever on one character, Emin herself.

Before My Bed,there was Emin’s startling live appearance on Channel 4 on the evening of the 1997 Turner Prize, when she rounded drunkenly on her fellow panellists – Waldemar Januszczak, Matthew Collings, David Sylvester and Norman Rosenthal, who were all pricelessly dumbfounded by her outburst – before lurching off the set and into the glare of a newfound celebrity. That was, arguably, her breakthrough moment, and might even be thought of as a piece of performance art in its own right, since it perfectly defined Emin’s perspective both on the world at large and on the world of art. “You people aren’t relating to me any more, you’ve lost me,” she complained, before woozily declaring that she had rather go off and have a drink with her friends. The encounter has been remembered as the tale of an honest young artist’s impatience with the fusty, rehearsed, academic debates of contemporary art criticism – which it was, but only in part. In the larger narrative of Emin’s career, it was simply the most public assertion yet of her enormous, compulsive egotism. The panellists had not lost her attention solely because they were talking about art in a particularly abstruse or annoying way. They had lost her attention because they were not talking about her. Getting people to talk about her – putting herself, her life and her problems centre stage – has always been Emin’s driving motivation. To her credit, she herself has never pretended otherwise.

When did Emin’s career begin, exactly? The answer to the question is not entirely straightforward. Before the appearance on Channel 4 there had been her grotto of self-disclosure, in the form of a tent hand-stitched with the names of family, friends and lovers and archly entitled Everyone I Have Ever Slept With 1963-1995 (a work which cannot be displayed because it was subsequently destroyed in the Momart warehouse fire of 2004); before that, participation in a number of group shows; but before that, the picture is less than clear.

The title of the retrospective in Edinburgh implies that two decades of work is on show, but the reality is closer to fifteen years. It is often assumed that Emin is a member of the generation tagged the Young British Artists, but the reality is that at a time when the likes of Damien Hirst, Gary Hume, Rachel Whiteread and Michael Landy were all very much in the public eye, no one really knew what Tracey Emin was about. She was a familiar enough figure in the early 1990s, although in a rather odd way, because while her work was so marginal as to be all but unknown, she had a habit of acting the part of raucous queen bee. If she threw a party, student friends with video cameras would materialise from nowhere, as if to make sure that everyone realised that this was an Event. It was only when Jay Jopling took an interest in her work, and invited her to show it, that she became known for her art rather than her antics.

One of the earliest works on display in the current show dates from 1992 and is a reconstruction of an exhibition first held in Jopling’s White Cube Gallery. Coyly entitled My Major Retrospective, it already implies the existence of a career that predates Emin’s official career, although one lost to a particular trauma. It consists of a multitude of tiny mounted photographs of the paintings that she had destroyed – more or less all her work to date – at the end of her degree year at the Royal College of Art in 1990. There is regret, here, mingled with hubris. She brandishes all that remains of her time as an art student – a shelf cluttered with simulacra of dead, destroyed objects – as if to assert that she is strong enough to survive the loss. Forget the faded memory of her own work, it is the artist’s personality that is really on display.

Resurrecting or exorcising trauma fast became her modus operandi, although she was soon looping back, far beyond her student years, to revisit the memories of what seems to have been a distinctly dysfunctional childhood in the seaside town of Margate. Exploration of the Soul, which she wrote in 1994, is a handwritten text pinned to the gallery wall in which the artist recalls a multitude of grim experiences from her childhood and adolescence – guilty sexual trysts with her twin brother, abuse at the hands of a male guest in her parents’ inaptly named International Hotel, a multitude of more or less soulless sexual encounters, interspersed with brief moments of ecstasy, ending with her actual rape in an alley close to the sea front.

This text is not exhibited as a work of art, although it is the font and origin of more or less everything Emin has created: the confessional hand-sewn blankets, banners of self-exposure harking back, almost always, to the teenage days of sexual abandon and abuse; the films, such as Why I Never Became a Dancer, in which Emin remembers a group of her old lovers chanting insults at her in a disco and revels in her escape from the narrow world of her own past; the drawings and lithographs, created in a style somewhere between that of Egon Schiele and Paul Klee, which translate distilled memories of an abiding unhappiness into smudged but forcefully diagrammatic images of the artist herself, naked and splay-legged in varyingly dire sets of circumstances.

Emin’s draughtsmanship is her greatest asset. Powerful and unsettling, it is the graphic equivalent of a fishbone stuck in the throat, or, to use her kind of metaphor, an interuterine device. Her art habitually plays on the contrast between such knowing pathos of form and the artist’s exultant sense that, notwithstanding everything, she has transcended the traumas that she records. Time and again, her work insists on the most detailed and flagrant demonstrations of what she has been through – My Abortion even includes a tiny vitrine containing what seem to be bloodstained gynecological swabs – only to declare that, somehow or other, she has managed to survive it.

There is no questioning the visceral force of Emin’s self-consciously confessional art, although the extent to which it represents the raw reality suggested by its rhetoric, or a mythologisation of the actual truth, is something only she herself will ever know. Again and again, she tells the tale of a pitiful, fractured past, made up of sad, transitory couplings and a string of other, equally abortive relationships. She is technically inventive and works in a multitude of media: words and images, collage and video, even reclaimed metal and timber that has been used to fashion the rickety big dipper of a sculpture entitled It’s Not the Way I Want to Die – a work that comes across as a ramshackle allegory of the roller-coaster ride of the artist’s life. But the suspicion lingers that this multiplicity of means has been forced upon her by the limitations of her subject matter. She speaks in so many different languages to create variety within her relentlessly single-minded story of the self.

The later rooms in the exhibition mark Emin’s return to painting as well as the apparent decline of her style. Soft-spoken, mannerist homages to the likes of Edvard Munch proliferate. Her recent work includes a light-hearted series of drawings of birds, which may amount to her own wry comment on the predicament in which she finds herself. “The neo-Expressionist angst woman with her legs wide open isn’t what I want on the wall at the moment … maybe sweet little birds drawn in my style would be really nice for the living room wall.” But joking apart, the dilemma remains. It is the Catch-22 for any artist whose work relies so heavily, for its power, on harrowing subject matter. As the passage of time takes her further from her own traumatic past, the more difficult it may be for her to sustain the interest of her work.