Patrick Bateman's existence is incredibly mundane. Outside of appearances (clothes, physique, being seen at the best restaurants) nothing matters to him. There is absolutely no mention of family until close to the end (and these brief glimpses into his family give us a bit of insight as to how he ended up this way without really being a sole "reason" for his state). The people closest to him are as vapid as he is (probably moreso). And because of this, they pay absolutely no attention to what are very likely cries for help. A recurring theme in the book is the absolute conformity of his peer group --everyone wears wool suits, slicked back hair, and horn-rim glasses-- to the point that no one can tell anyone apart, which aids him in his ability to blend in and get away with the killings. It's a very well written commentary on the socio-cultural state of the time. Another interesting aspect to this book is Bateman's dissociative perspective in terms of his victims and personal attachments (if you can call them that), while he speaks passionately about pop music. He goes into tactile diatribes about Genesis, Whitney Houston, and Huey Lewis, but is emotionless when it comes to the murders and even attire (which he obsesses over). He speaks endlessly about clothes and designers, but even as he passes judgement on the attire of others and obsesses over his own, he does not seem to extract any joy from it. It's just something he does almost robotically. Pop music seems to be the only thing he actually enjoys, though even his reviews on the subject seem detached. Despite being descriptive to the point of being almost flowery, they are written in the passive voice.

EDIT: Sorry for the wall of text. I pulled this from my Goodreads review.