More About American Psycho

'American Psycho' follows Wall Street banker Patrick Bateman, whose obsession with wealth, status and perfection masks an increasingly disturbed mind, leading him into a world where violence and reality become impossible to separate.
Yes. The film is based on Bret Easton Ellis's 1991 novel of the same name, though it softens some of the novel's most graphic content while preserving its satirical themes.
The ending is intentionally ambiguous, leaving open the question of whether Patrick Bateman's murders actually occurred or were the product of his deteriorating mental state. The uncertainty reinforces the film's satire of identity, consumerism and moral emptiness.