What happens when bad children happen to good parents? Does it mean they are not, in fact, as good as they had imagined themselves to be? With these questions, British director Lynne Ramsay has created a nihilist tale of guilt and horror. Working with co-writer Rory Kinnear, she has adapted Lionel Shriver’s prizewinning 2003 novel – whose much-spoofed title is now part of the language – about a woman whose teenage son Kevin has committed a Columbine-style massacre.

This adaptation raises a subject which has eluded other films on the same subject, such as Gus Van Sant’s Elephant or indeed Michael Moore’s documentary Bowling for Columbine: the subject of the aftermath. Kevin cannot be tried as an adult. So who, in the end, will wind up getting the blame for a teenage boy’s psychopathic rampage? Why, the mother of course, like the Blessed Virgin absorbing reflected adoration of the crucified Christ.

Tilda Swinton plays Eva, a former free spirit and city-dweller who has found herself having to move to the suburbs because of her husband Franklin (John C Reilly) and his breezy insistence that the city is no place to bring up children. They have two: obnoxious smartmouth Kevin (Ezra Miller) and sweet younger sister Celia (Ashley Gerasimovich). Her success as a travel writer originally meant they could afford a handsome family home, but we join the story as Eva, her life in ruins, is living on her own in a scuzzy bungalow, a pill-popping drinker. Kevin’s grotesque crime means her car and porch are always vandalised and she cannot leave the house without being screamed at or assaulted. She must spend the rest of her life trying, vainly, to make up for a crime for which she is not responsible and which she does not understand. She is simultaneously at the centre of this event and at its margins.

So Eva takes stock of her life and tries to find out if there was one key, terrible misjudgment or failing of hers as a mother, which set her son off on the road to murder. Swinton portrays Eva as a ghost, haunting her past and haunted by it. She is gaunt, hollow-eyed, stunned: her eyes are almost blind, as if she can see only memories. And perhaps it is not that she created Kevin, but that Kevin created her. Eva’s only identity is now that of someone who gave birth to horror. When Kevin’s parents break off arguing one night to tell him, patronisingly, that he might not understand the “context” to their quarrel, he sneers: “I am the context.”

From the first, it is clear that this is the worst case of post-natal depression in history, and perhaps the violent dénouement is its ultimate symptom. From the first, Eva doesn’t like her baby and her baby doesn’t like her. She can’t stop him crying and, in the extremes of desperation and sleeplessness, coos at him satirically: “Mommy was happy before Kevin came along.” Ramsay’s film amplifies a central, emotionally incorrect theme: motherhood itself is a ritual in which the adult consents to gradual parasitic destruction. Maybe it’s movies like this and Rosemary’s Baby that are voicing forbidden fears, or even truths, about being a parent.

As Kevin grows to infanthood, he resents his baby sister and is diabolically intent on upsetting and disconcerting the once confident, successful Eva. He appears deliberately slow to speak and, particularly, to potty train. On this point he succeeds in goading Eva beyond endurance and then, with satanic cunning, securing her guilty submission by covering up Eva’s violent overreaction. Finally he becomes a teenager and Ezra Miller is a compellingly sensual nemesis, coolly set on the anti-Oedipal plan of befriending his dad and destroying his mom.

Plenty of kids act up. Did Eva go wrong? Was it with bedtime stories about Robin Hood that encouraged his interest in archery? Or in dangerously teasing Kevin about being obviously impressed with the big photo of her in the bookstore window? Or did he just generally inhale her miasma of resentment, her own physiological disenchantment with motherhood itself?

And what does an independent-minded, career woman do when she is landed with a nasty little boy, precisely the kind of smug competitive male she has spent her whole life trying to subdue and surpass? What American Psycho was to consumerism, We Need to Talk About Kevin is to both sexism and feminism, a brilliantly extreme parable, operatically pessimistic. In the end, the audience is left with the same unanswerable question: what made Kevin do it? Nature or nurture? A mother supplies both. Kevin is flesh of her flesh and perhaps an inability to judge him is her awful biological destiny. It is tremendously acted by Tilda Swinton (a performance to put aside her protective mother in David Siegel and Scott McGehee’s 2001 thriller The Deep End) and by Ezra Miller, with inspired images from cinematographer Seamus McGarvey.

My only worry is that some hapless cinemas might schedule this as one of their special “parent-child” screenings. Bad idea.