Well if you want similar stories of addictions etc then watch LEAVING LAS VEGAS, MIDNIGHT COWBOY or the superb TV series BREAKING BAD.
This movie is from a Bret Easten Ellis novel and they always suffer from 1) having spoilt rich characters that not many can relate to, and often behaving so horribly you do not care at all if bad things happen to them; 2) an almost worship of money, bling, wealth which always leads to poetic justice.
It is all very 80s and all totally MEH really - I watched it, shrugged, then turned off.
As ever in these films, the massive addicts never look as bad as real ones (cf WOLF OF WALL STREET) so it';s hard to believe in the characters really and suspend disbelief. ALSO the SHOCK HORROR revelation (no spoilers) would not be so shocking today in our pansexual transanything world. That happens with novels too - a shocking unmarried mother in novels of even 50 years ago is almost standard these days.
So, it's all very 80s, and fun to look at the hairdos and cars and clothes etc - but I did not care about the characters at all. The musicis all pretty awful west coast US 80s tracks rather than the superior early 80s UK synth stuff.
2.5 stars rounded up.
My brief reading online explains why the film ended up the way it did (producers, studios) but I was still left wondering. "Why?" Bret Easton Ellis' novel is about a nihilistic, spoilt teenager floating through life doing pretty much what he pleases. The film however is turned into a moral tale of drug abuse. Shame, because I think American Psycho proves how well Ellis' books can be adapted into films.