And so to film. There always was going to be film, even if for a while we drifted in the kind of surrealist sea only a buttfuck-coupling of out-of-control bad-boy Oliver Stone and pert pretty poser Leonardo DeCaprio could offer. Imagine - Patrick Bateman, all comely pecs and floppy blonde fringes!

Instead, Briton Christian Bale is Ellis’ wheeler dealer into mergers and acquisitions ("murders and executions"). We never actually see him do much of anything, though, beyond comparing metaphorical dick sizes with the guys, dragging around with an ostensible fiancée (Reese Witherspoon), or flirting with the secretary (the excellent Chloë Sevigny). Oh, and killing people. Bateman likes that just as much as making money. Knifing a bum, abusing hookers, axing business rival Paul Allen (Jared Leto). Tuning up a chainsaw (Patrick’s exercise vid of choice is Tobe Hooper’s infamous Texas excursion) and playing gore-washed changing rooms with Allen’s deserted apartment.

But how, how to film the unfilmable? Well, for the most part director Mary (I Shot Andy Warhol) Harron and co-writer Guinevere Turner (likeable lesbian empowerer Go Fish) simply don’t. Instead of what, we presume, would have been Stone’s compromised and depressingly literal Vogue charnel house, the finished film is coy about Bateman’s Tourretic savagery. Violence is depicted in almost abstract terms: as blood spattering Bateman’s plastic raincoat; as corpses bagged and tagged with supermarket super-freshness; a disembodied head next to the sorbet. American Psycho asks us to accept the novel’s excesses even before it begins. Or at the very least as it begins - with what we assume is blood dripping on perfect white surfaces to the sound of John Cale’s delicious score. Harron colludes with her audience.

Bale is terrific. It is his picture after all. From scrawny glam bi-boy in Haynes’ genius Velvet Goldmine to monstrous gym-bunny in one horrifying leap. Bateman’s routines are all 80s minimalism: decoration, art, his ablutive rituals. He is a vessel into which every drop of that vacuous decade can be poured without touching the sides. Bale absorbs Bateman, suggesting the effort in his technique even as he reflects nothing back. He keeps his cruel nature secret from everyone but us. This is Patrick Bateman.

In this place everything has its price and he the biggest bankroll. The most chilling moments occur not when the blood-soaked yuppie charges naked down a corridor toting a smoking chainsaw, but when he admires himself in the mirror, fucking. Sex as porno chic with himself as buck star. Bateman’s sexuality is indeterminate; he’d exclusively fuck himself if he could. Or when a hooker he previously abused enough to put in the ER reluctantly agrees to another liaison just because he can write a big enough cheque.

Harron fights to define a unique palette from which to paint, and the results are a curious blend of Wall Street (there’s irony) and Abel Ferrara. (It’s not fanciful to imagine Driller Killer excluded from Bateman’s work-out wish-list simply on account of its punk score; his awed deconstruction of the majesty of Genesis and Whitney Houston is hilarious.) The picture so often looks like those – Bright Lights, Big City, The Secret of My Success, Less Than Zero – it ostensibly digs in the ribs. Superficial grain and texture that has dated as badly as anything run through the Lumières’ own camera. The details – mobiles the size of house-bricks, power braces – are frosting on an already elegantly naff cake.

Sensibly, too, the picture finally upends itself. Bateman, his tenuous grip on reality faltering, fights a running gun battle with the NYPD before confessing all to his lawyer’s answering machine. No one understands, though, because not one person in here listens to either the incessant babble or the horrified screams; the white noise drone in which the novel is framed. Except when someone lets slip that Paul Allen is alive and well and in Europe. Then you can hear a pin drop.