I've always thought that some of them were real and some of them were not real, much for the same reason yuppies cannot be determined from one another.

I wouldn't listen to her either, I don't think she did that good of a job adapting the book, anyway. The films enjoyable because of the actors involved, I thought it was mediocre otherwise, and didn't feel nearly as depraved and crazy as the book.

Didn't the first cut of the movie get an x or nc-17? I think she may have been hamstrung to get the R she was eventually able to get.

According to imdb:
Not surprising that it was the sex that the MPAA was more concerned about.

This movie would be a real disappointment if the killings really took place.

It's obvious to me it's in his head when one minute he's chasing someone with a chainsaw and the next minute he's doodling the scene on a sheet of paper.

Years ago in a magazine interview, co-screenwriter (and actress) Guinivere Turner said, "When we wrote the script, we wanted it to be absolutely clear that he is actually killing people...And that's not what people are coming away with. They think it's all a dream, or all a fantasy. I was doing a roundtable discussion with a bunch of journalists, and this guy's first question was, 'So did he do it or didn't he?' And I said he was really doing it, so he turns to the woman next to him and says, 'See?'"
The great thing about the film American Psycho (as opposed to the book) is that by the time it ends the film is almost a "lady or the tiger" conundrum. How you interpret it depends on what presuppositions you bring to it. After first seeing it theatrically, I thought the intent of the film was obvious. The "I got mine, screw you" culture of the '80s(an amped-up and absurd version of the '80s, where a restaurant menu could be stamped in braille on stainless steel) was in essence doing Bateman's clean up work for him and no matter what unspeakable acts he could commit he'd never face any real consequences, much like Robert Chambers in '86. But I like hearing the interpretations of those who see it otherwise.

I thought he did them - the point was that society cleaned up his mess...in that sense he is ultimate expression of that society.

I guess the reaction of the real estate agent was probably the biggest clue that it was real, but who knows. Its an interesting movie to see every few years

There are some scenes, however, that I do think are in Bateman's head. The ATM, the action movie shootout, those all things he probably was imagining. But I think the murders actually took place within the context of the movie.

Has Brett Easton Ellis ever addressed the question?

Just about every time I watch it I change my mind about whether it's real or not. Currently at not real, but that's subject to change.

IIRC I read an interview with Ellis where he explicity stated that the murders were in Bateman's head and he didn't actually do any killing. I think you can make a valid arguement for either side, but personally I've always felt that everything was in his head and these were his delusional fanatasies to escape from the monotony of his daily life.