Darren Aronofsky's Requiem For A Dream, a bold portrait of drug addiction which made its world premiere at the Cannes Film Festival this year, has run into censorship trouble in the US where it is being released by Artisan Entertainment.

The Motion Picture Association Of America (MPAA) yesterday gave the film a prohibitive NC-17 - a rating which many US cinema chains won't screen and for which many newspapers won't accept advertising. The MPAA cited sexual elements within the film as the reason for its decision - clearly referring to a scene of sexual degradation between two women towards the film's end. Sexual content was also cited in the original NC-17 ratings for Mary Harron's American Psycho earlier this year and for Stanley Kubrick's Eyes Wide Shut.

Yet, unlike the makers of those films, Artisan said yesterday it will not seek to make cuts to the film. In a statement made yesterday, company CEO Amir Malin said: "As the distributor of Requiem for a Dream, Artisan Entertainment believes that the NC-17 rating assessed by the MPAA is neither correct nor justified. We have been informed that the rating assigned to the film is in response to sexual elements within the film. In this film, sexual imagery is not gratuitous and far from prominent and the context of sex is used only in support of the story and the situations in which the film's characters find themselves. We intend to stand by director Darren Aronofsky's cut of the film and will not change a single frame of this important work. Artisan believes that audiences should not be censored from any elements of Requiem for a Dream including those very limited scenes which are of a sexual nature and this NC-17 ruling seeks to do just that. We support an R rating for adult subject matter and in this case we strongly believe an R rating is appropriate. We are currently appealing the ruling of the MPAA and if our appeal is not granted, we will release the film un-rated."

Adapted by Aronofsky and Hubert Selby Jr from Selby's seminal novel of the same name, Requiem For A Dream follows a group of drug addicted characters from the exhilerating highs to the agonising lows of addiction. It stars Jared Leto, Jennifer Connelly and Marlon Wayans as three heroine junkies and Ellen Burstyn as Leto's mother who is hooked on diet pills. Burstyn's performance is already being tipped as a contender in the end of year awards rounds.

Ironically Requiem For A Dream is so harrowing in its depiction of addiction - and the degradations people will go through to get a fix - that the sexual scene in question seems a random one for the MPAA to pinpoint and its decision will no doubt exacerbate criticism that it unfairly focuses on and penalises sex in artistic films made for adults. Last year, many were riled by the MPAA's decision to give Eyes Wide Shut an NC-17 on account of copulation in its central orgy scene. In order to secure an R rating, Warner Bros then supervised a digital cover-up process whereby some of the copulating couples were concealed by dark CGI-created figures. Similarly, outrage was expressed when the MPAA opted to penalise threesome sex scenes in both American Psycho and James Toback's Black And White, both of which were then re-edited and released with R ratings.

Critics were glowing at Requiem's out-of-competition screening at Cannes and it has been selected for the Karlovy Vary, Deauville and Toronto film festivals. Artisan plans to release Requiem For A Dream on Oct 6 in New York City.