One thing that really striked me in the film was the very vague themes of necrophilia. I mean, Norman Bates actually loves the people he kills, so it is quite strange, as this is a sort of necrophilia. In reality, Hitchcock was a very adult director- he delt with very adult issues, but uses them subtly in the film. For example, when Northhill meets Kendel on the train in "North by Northwest", and they start making out, Kendel says some really, really rude stuff. She starts flirting with him- and saying some very innapropriate things for that time. I kept wondering if these films were pre-code films, but then I researched it and found out that the Hays Code came about in the 30's due to some sexual films being released because of the Great Deppresion. I think films like "Psycho" and "North by Northwest" were not targeted for general audiences; just adult ones. My reasons? Well, those before and the fact that when "Psycho" was released in director's cut format, it garnered an R-18 rating.
That reminds me- Bela Lugosi was in quite a few precode horror films as well- his most famous was that of "The Murders in the Rue Morgue". That sort of had to be done at that time to avert the law, as it had things like ape blood being pumped into the victims bodies (Don't look at me, look at the original novel by Edgar Allan Poe). Have you seen any precode films?