Depressing doesn’t come close. Now here comes Andrea Arnold, the queen of gritty urban drama to Ken Loach’s king, to pour more liquid on your chips with her latest, Fish Tank.

Arnold’s tale of an Essex teenager kicking and scratching at life isn’t the easiest of sells, yet it’s among the most powerful, affecting films you’ll see this year. There is ugliness here, and despair to choke the most optimistic of horses, but there’s beauty too, and a central performance by newcomer Katie Jarvis that’s a genuine joy to behold.

Fish Tank is set in that country that has come to be known as Broken Britain (copyright Dave Cameron). You know the place. It’s a land of feral teens in hoodies, high rise blocks that make the soul sink, drugs, dysfunctional families, no hope, no happiness, no fun.

Jarvis plays Mia, a friendless 15-year-old in possession of her own CD player, a selection of trackie bottoms and a social worker. Mia loves to dance and hates to go to school, hence the social worker. She lives with her useless mother and gobby little sister on a council estate that would have embarrassed the worst of Stalin’s architects. No wonder her face is set in a permanent scowl.

Mia and her mum (Kierston Wareing) are close, but give every impression of hating the very innards of each other. Picking up on this, and naturally exploiting it with glee, is the youngest child, played by Rebecca Griffiths. Like Jarvis, this is Griffiths’ film debut but you’d never know it the way she fires off her wickedly wry lines. “I’ve got Childline’s number here if you need it,” she teases Mia after there has been another screaming match with mum. That’s about as light as the humour gets. It’s not Balamory, but it can be bally funny.

Mum is never truly happy unless she’s with a man, and her latest is Connor, a security guard armed with an easy Irish charm. Connor (Michael Fassbender) is all for making friends with the girls, which is fine by the youngest but Mia is more sceptical. Slowly, he wins her round and what looks like a contented enough little family begins to emerge.

Mia’s problems are not about to be solved by a day out to a country pub, however. “When she was born she cried for days,” her mum tells the social worker. “It was like she came out looking for trouble.” But sometimes, as writer-director Arnold shows to blistering effect, trouble can come looking for you, and then what’s a girl like Mia to do? Sink, or swim?

Jarvis turns in a magnificent performance. Mia is a kid you’d cross a region to avoid, yet Jarvis breaks down those barriers of prejudice, sometimes with a toothpick, occasionally with a sledgehammer. Mia is a mess, but she’s also a youngster capable of great kindness and one, moreover, with a fierce – if warped – sense of right and wrong. Life has done this one some bad turns, but she’s not about to roll over and play dead just yet.

If Mia is the angry heart of Arnold’s film, her fury is balanced beautifully by Connor’s relaxed, optimistic nature. Fassbender has had quite a few finest hours lately, Hunger and Inglourious Basterds among them. Fish Tank is easily on a par with those.

Arnold’s film is all about contrasts – the vivid drama playing out against a backdrop bleached of colour; the bouts of verbal violence punctuated by periods of Zen-like calm. Ugliness is everywhere, but so is beauty, whether it’s in a look of childlike hope skipping across Mia’s face when she sees a flyer for dance auditions, or a view from a tower block of an endless blue sky.

Above all, there’s the contrast between the chaos on screen and Arnold’s ferocious grip on the story. Conversations tumble into each other, scenes come and go in no obvious storytelling order, but don’t let the apparent lack of control fool you. Everything in Arnold’s film is measured, coiled and waiting to pounce on your assumptions. Watching such a movie can be exhausting, distressing – some of the latter scenes fairly put the nerves through a mincer – but it’s electrifying, too.

Jarvis won best British performance at the Edinburgh Film Festival. Fish Tank, like Arnold’s previous film, the Glasgow-set Red Road, picked up the jury prize at Cannes this summer. Both awards book-end her Oscar for the short film, Wasp.

Prizes aplenty, similar terrain explored, but where Red Road felt like just more misery tourism – and Glasgow has been there and done that – Arnold’s latest plays against expectations and towards hope. Broken Britain might still be her domain, but where other directors can see only shards of glass, Arnold has a good and true eye for any diamonds lurking miraculously within.

Fish Tank (15)

****

Dir: Andrea Arnold

With: Katie Jarvis, Michael Fassbender