His equally virtuoso follow-up Requiem for a Dream left me feeling much the same, as if I'd been brutally trepanned with a sophisticated surgical instrument. Aronofsky's film is wildly self-indulgent, dangerously drunk on its own technique - and that rankles all the more because as a director he is, in a way that's hard to ignore but harder to warm to, rather brilliant. Darren Aronofsky's first film, the arguably empty but undeniably dazzling paranoid-maths thriller Pi, ended with its hero drilling a hole in his own head. His equally virtuoso follow-up Requiem for a Dream left me feeling much the same, as if I'd been brutally trepanned with a sophisticated surgical instrument. Aronofsky's film is wildly self-indulgent, dangerously drunk on its own technique - and that rankles all the more because as a director he is, in a way that's hard to ignore but harder to warm to, rather brilliant. Pi's fascination derived from the combination of a cerebrally arcane story with an intense, vibrant style owing more to the boosts and beats of hip-hop production than to standard narrative editing. For his follow-up, Aronofsky gets unequivocally down and dirty.

It's an adaptation of Hubert Selby Jr's 1978 novel of addiction, and is certainly faithful to the original; in fact, Selby collaborated with Aronofsky on the screenplay. Like the book, it details the parallel descents into hell of Sara Goldfarb (Ellen Burstyn), an ageing Brighton Beach widow, and her junkie son Harry (Jared Leto). Harry's uptown girlfriend Marion (Jennifer Connelly) and sidekick Tyrone (Marlon Wayans) also figure, but in both film and book, it's the mother-and-son parallel that gives the story its meat, and its alternating structure.Harry and Tyrone dream of being successful heroin dealers, but can't resist their own wares, while Sara is hooked on TV - specifically, on a come-on-down evangelical extravaganza for slimmers, hosted by Tappy Tibbons, a hysterically brassy populist who makes Jerry Springer look like Tom Paulin. (Christopher McDonald is lazy casting as Tappy - since Robert Redford's Quiz Show this actor's presence has been screen shorthand for all-American TV insincerity.) Offered the chimerical prospect of being a studio guest, Sarah dreams of slimming for the red dress of her youth, gets hooked on diet pills and skids towards gibbering perdition.In the novel, the characters' downward momentum is inexorable, although Selby's compassion emerges through his stream-of-scrambled-consciousness style, which gets inside the characters' demotic and so into their souls. The film is just as relentless, but Aronofsky's stylistic instinct is constantly to blind us with invention, feeding us hot bursts of imagery to keep us interested - to get us hooked, you might say.There are certainly some astounding tricks in his repertoire, not to mention those of photographer Matthew Libatique and editor Jay Rabinowitz. The editing is a non-stop tour de force, Rabinowitz particularly excelling at split-screens: in the most memorable sequence, as Harry and Marion lie in bed, we see one person at a time in close-up, while on the other half of the screen, a disembodied hand caresses various body parts.Other effects shout loud and say nothing.

Fast motion, slow-motion, distorting lenses, fantasy sequences (cascading phantom doughnuts, a monster fridge with a feral maw).. But most of it feels like comic-strip literalism. The first time Harry shoots up, we get a rush of short, sharp close-ups - clenched teeth, blood corpuscles, syringe, popping eye pupil, some 13 shots in six seconds, all to rhythmic sound effects. It's stunning the first time, but the trick recurs with variations throughout the film, and becomes immensely grating. It functions as a sort of visual chorus, as in a rap mix, but I suspect Aronofsky also wants to convey the monotony of addiction, and such a refrain may be a technique better suited to page than screen.What's missing is a sense of humanity. These self-deceiving junkies are going nowhere, and the film doesn't much allow us to care about them (it certainly doesn't care much for the black character Tyrone, reducing him to a one-dimensional street-smart bystander) But at least Aronofsky makes their looks work. An astute stroke is to cast Leto and Connelly as lovers - with dark brows and big black moppet eyes, they look like siblings, highlighting their romance's self-enclosed, incestuous quality. While Leto is blankly beautiful, never more than dazed and floaty, Connelly is the best thing in the film.

After years playing vacant ingénues, here she is a tarnished sophisticate, oddly grubby and lascivious. Connelly delivers the film's most intelligent, most self-aware performance, and Aronofsky ends up wasting it - one of his crassest images is of the doomed Marion putting on her make-up, a single tear rolling down her blank face.Such sentimentalism goes hand in hand with an overall callousness. Sara undergoes a ghastly abjection, turning from a joke Jewish mother into a ravaged monster/martyr. Burstyn gives a really bad performance masquerading as a great one - a shamelessly ingratiating barnstormer, all hand-wringing pathos, always a crack and a quaver in her voice.

There's nothing tragic about Sara's descent because she is presented as a hysterical fool from the start. In one scene, she dances to a Latin rhythm, and the music and editing cruelly contrive to make her look lumbering, buffoonish.Aronofsky can't be faulted for precocious confidence, but he plays the screen with the cold ruthlessness of a brilliant 12-year-old cruising his way through Tomb Raider. Tappy Tibbons' TV mantra is "Be excited! Be excited!" - and Aronofsky's hyperventilating insistence drums away at much the same message. The irony, considering the theme, is that Aronofsky himself is badly addicted to the visual hit, and the film itself gets increasingly dependent on bigger and more powerful thrills. By the time you've been through the final inferno - an endless montaged ordeal of electro-shock, gangrene and double-pronged dildos, with a cameo from Selby himself, a wizened, cackling homunculus - you're exhausted rather than enlightened, wiped out rather than wised up, and ready for a good long rest at Betty Ford's. Aronofsky's next project, supposedly, is a new Batman movie, and somehow I can't see him going cold turkey on that one..