Helen Walsh has lived a little. At 13, while her classmates in Warrington were flicking through Smash Hits, she was swept up in the early 90s euphoria of acid house and ecstasy. At 16, as most girls her age sat their GCSEs, she was hooked on cocaine and receiving death threats from dealers. At 17, while many of her peers were planning for university, Walsh was in Barcelona, picking pockets by day and working as a ‘fixer’, hooking up men in transvestite bars with prostitutes, by night.

Thirteen years on, in advance of the release of her second novel, Once Upon a Time in England, Walsh sits across from me in Liverpool’s Blackburne Arms, a favourite haunt of Millie O’Reilly, the central character in Walsh’s debut fiction, Brass. In many ways that book proved her saviour. A cathartic outpouring, written at her mum’s kitchen table in 2003, it pulls no punches as Millie, a middle-class, semi-suburban 19-year-old girl, obsessed by Liverpool’s seedy underbelly, binges hard, fast and relentlessly on pills, powder, whisky and rough sex with prostitutes and hard men alike. An almighty clearing of her creative lungs, the book won Walsh the Betty Trask debut writers prize, and had her hailed as an explosive new literary talent.

If Brass marked Walsh’s arrival as a voice, Once Upon a Time in England signals her emergence as a serious novelist. Where her debut was naked, angry, uncompromising and occasionally frantic, the follow-up is more focused, plot-driven, sensitive and romantic in places, if no less disturbing in others. A tale of ‘doomed love and its repercussions’ set in Walsh’s native Warrington from 1975–1989 against a backdrop of urban decay, poverty and rising subscription to the National Front, it follows the Fitzgerald family – Irish father and gifted soul singer Robbie, Malaysian mother Susheela and their mixed-race children Vincent and Ellie – as they struggle to survive. Beset by eternal misfortune, yet somehow still deeply passionate and aspirational, they’re a family who could etch themselves into the stoniest of hearts.

‘It came in the wake of my reading Theodore Dreiser’s An American Tragedy,’ she explains, of Once Upon a Time in England’s origins. ‘It’s that whole kind of stand-off between existentialism and fatalism; that fate is determined by environmental constraints and hereditary predispositions and that, in a sense, there’s no free will. I wanted to do that with the Fitzgeralds. Robbie and Susheela are doomed right from the very beginning.’ Within the first few pages Susheela has been subjected to a sickening, racially motivated sexual assault. It sets her young family on a slow downward trajectory over two decades. Robbie has to give up on his hopes of stardom and submit to a soul-destroying nine-to-five factory grind. Susheela, traumatised and disenchanted, grows distant from her husband and pines for Kuala Lumpur. Vincent is a talented writer, but also reclusive and effeminate and picked on for it, not least by his father. Ellie is an intelligent, lovable tomboy, but is lured off-piste by ecstasy.

Like Brass, Once Upon a Time in England is a deeply personal novel. Walsh’s mother too is Malaysian, and married to a musician. Together, they raised a mixed race son and daughter, ‘the only brown kids on an all white estate’, as Walsh puts it. It’s not autobiographical, she insists, but more so a fictionalised tale superimposed onto elements of her own reality. ‘There was a time towards the end when I think those boundaries did kind of blur though,’ Walsh admits.

Particularly in the case of Ellie, who experiences a spiritual awakening of sorts upon discovering acid house at the Warrington nightclub Legends, just as Walsh did in 1990. The scenes there are vivid and euphoric: a manifestation of the reverence in which the author holds her memories of the time. In the novel, the divergence from her reality comes when Ellie is shocked into realising how transient the experience is. Walsh clung on to watch acid house die ‘a very slow death of self-parody’, as the ‘pills got shite’ and the music found its way onto Top of the Pops.

‘Because I was so young and naïve and vulnerable, I saw it (acid house) as something more profound and infinite than it actually was,’ she explains. ‘When it collapsed, it was like, “Fuck, I’ve invested so much. I’ve basically messed up my relationship with my parents and severed the umbilical cord with everyone and everything to be part of this quasi-family that actually, outside the dance floor, doesn’t exist.” When it crumbled a number of people felt phenomenally let down and cheated and moved into heroin.’

Walsh moved into the only marginally less seedy and dangerous world of cocaine. ‘I was incredibly naïve and would accept drugs for freebies from anyone and everyone thinking it was all part of the beneficent spirit of ecstasy culture. This kind of debt came home to roost.’ Fearing for her own and her parents’ lives, she made a midnight bunk to Barcelona. There she snorted herself into such a depressed, broke and paranoid stupor that she was scared to leave her apartment. Her mother, ever faithful, would dutifully send her daughter a tenner every few weeks. Walsh eventually travelled back to England, started a sociology degree at Liverpool Uni and began a long process of sobering up, the end result of which was Brass.

‘That book really was me calling time on all that kind of heavy indulgence,’ she says. ‘It was a purge. Almost like lancing a boil. Because it was so, so easy to write. There was no struggle, no crisis of confidence, it really just wrote itself.’ Writing Once Upon a Time in England was a much more complicated, pressured process, partly because of the weight of expectation, partly because Walsh knew she was laying herself bare again. She finds it far easier discussing her work with journalists and strangers than she does friends and family. ‘I find it difficult talking about books and writing and owning up to being a novelist, because it’s all incredibly personal. Even if I’m writing a short story on a subject that has absolutely no autobiographical element whatsoever. I’m incredibly anxious when I have to hand it over to the outside world, and I feel incredibly naked and exposed.’

Writing fiction doesn’t have to be so personal though; Walsh just chooses to make it so. And it’s that, perhaps more than anything, which renders both novels such compelling reads – the constant interplay between imagination and tangible, gritty fragments of a real life, lived, for better or for worse, to extremes. Casting a look back over her teens, as she did when writing Once Upon a Time in England, did it make Walsh feel lucky that she has gone on to become a successful author, rather than something much grimmer? ‘Definitely. But I don’t think there’s any kind of turn I’ve taken, left or right, that’s come to haunt me. I think if I’d ended up in a deadend nine-to-five job, or a heroin addict, I might look back and lament those periods of my life and regret that I’d made wrong decisions. But if you can utilise or appropriate it in a way, nothing’s wasted.’

Once Upon a Time in England is published by Canongate on Thu 13 Mar.