Films about abuse have to be very careful. They can't be too harrowing you risk triggering audience members who have suffered through trauma, but if you're not harrowing enough you risk trivialising those who have survived – and those who haven't – abuse. The remarkable thing about Mary Nighy's feature debut Alice, Darling is that it is both a very difficult watch and surprisingly lowkey in its depiction of abuse.

Unlike a film like Nil by Mouth which puts the abuse on screen in such a way that it becomes impossible to watch, Alice, Darling shows us the after effects of emotional abuse. We don't have to suffer through a man hitting a woman, instead what we see is a portrayal of a more insidious abuse – coercive control. We meet Alice (Anna Kendrick) who appears uneasy in the presence of her friends Sophie (Wunmi Mosaku) and Tess (Kaniehtiio Horn) when they make pacing jokes about a waiter being into her.

The three of them go on a long weekend for Tess' birthday but in doing so Alice lies to her artist boyfriend Simon (Charlie Carrick). What we see is the lingering effects of words on a person. Much of the film is spent watching Kendrick literally pull her hair out, panicking that her boyfriend won't love her for doing things any reasonable person would do. It's subtle the way in which screenwriter Alanna Francis reveals the words and phrases Simon has used to manipulate Alice. Commenting on her sugar intake, making her feel stupid for wanting things, demanding to see her phone or checking her emails.

One scene of Kendrick and Horn out on a lake where Kendrick loses her earrings is painfully upsetting for how frantic she becomes, almost drowning herself in a search for lost items. We see the frustration friends have, not fully understanding the gravity of the situation and wondering where their loved one has gone.

For her part Kendrick is sensational. Scenes of her gasping for air in the bathroom after an argument are heart breaking. This might be her best performance to date, trading on that goodwill we have for Kendrick – and fantastic singing voice – but allowing her to plunge depths we've not yet seen. Both Horn and Mosaku are great too, in any other year these three would be fated with awards for their turns. Moments of Mosaku looking concerned are heartbreaking but a climactic stare down from Horn is as powerful as any monologue could ever be.

The film is one that burrows into your being, using occasional humour to build a sense of a person being kept down. One very important line “she looks like herself again” is simple but emotionally huge. Nighy never opts to linger on the body – we see that Alice's hair pulling has left her scalp red and painful, but it's never about the pain she has inflicted on herself, it's about the state of mind that has been created through micro-aggressions.

Nighy's film, like words, burrow deep into the soul and linger there far longer than actions ever could.

Alice, Darling is released in UK cinemas on January 20th