The novelist Donal Ryan has won the 2013 Guardian first book award with an angry portrait of rural life in post-crash Ireland, The Spinning Heart.

Speaking during the ceremony at Tate Modern in London, the writer said he found it difficult to believe that he had won.

"I can't believe it," he said. "I know everybody says it, but I really can't."

He dedicated the award to all writers "working at their beginnings".

"Of the many obstacles that stand in the way of a first book as it makes its precarious way into the world and into its readers hands," he explained, "fear is often the biggest and the most difficult to surmount. Fear of not being good enough, of not being able to say what we mean."

Born in a north Tipperary village in 1977, Ryan wrote the first draft of the novel in the summer of 2010, as economic collapse and deep cuts left one in three under the age of 30 unemployed.

Told as a set of interlocking short stories, Ryan summons up a chorus of voices struggling to make ends meet in a village near Limerick – an out-of-work foreman, a single mother living on an brand-new estate full of empty houses, an ex-apprentice heading off to Australia to look for work. These first-person accounts explore the scrabble for work in austerity Ireland and the bitter conflicts which blight families from generation to generation.

Writing in Guardian Review earlier this month the author explained how the characters articulate "their frustrations, fears, desires and sadness" one by one.

"When asked what the book is about, I often pause for too long and then mumble something about a village and the recession and polyphony and watch as the person's eyes glaze over," he wrote. "I desperately add that there's a murder – and a kidnap! – but it's usually too late."

Villages are fascinating clusters of humanity, he added, where drama springs from proximity. "In villages of all types we peer closely, watch one another, speculate, arrive at conclusions both wild and sane about our neighbours and ourselves." At the heart of the novel is the story of a marriage and the relationship between a father and a son, he continued. "Human relationships are, to borrow from James Salter, all that is. There are a million words and an infinite number of ways of combining them but we're all in pursuit of the same truth; we're all trying to explain ourselves."

The chair of the judging panel, Guardian Review editor Lisa Allardice, paid tribute to the "raw talent, promise and originality" exhibited by all the shortlisted writers, but said The Spinning Heart stood out for its "startling audacity".

"It may be slim in size, but it is hugely ambitious in structure and devastating in its emotional impact," she said. "Too often contemporary fiction is criticised for not engaging enough with contemporary issues, but this breathtakingly empathetic account of a community crumbling under the pressures of the recession deserves to stand as a companion piece to Anne Enright's wonderful The Forgotten Waltz, also set against the boom and bust of recent Irish history."

Allardice was joined on the panel for the £10,000 award by the psychotherapist and author Susie Orbach, the novelists Rachel Cusk and Philip Hensher, and Channel 4's Paul Mason.

The Spinning Heart was longlisted for the 2013 Man Booker prize and chosen as the Irish Book awards book of the year in 2012.

The Guardian first book award looks for the best debut work in any genre. Ryan joins a roster of winners including Zadie Smith, Chris Ware, Yiyun Li and last year's winner, Kevin Powers.