I don't think there was much of a difference. Effectively BNW=1984+drugs, but because there are no such drugs, 1984 is the only implementable option, pseudo-BNW is unsustainable, doesn't solve their problems and so is just a detour, because they couldn't go 1984 directly due to technical problems.
ISTM the advertising, entertainment and social-media industries are aiming to fulfil much of the role of BNW's drugs, and the pharmaceutical companies can probably cover most of the gaps.
I don’t belive 1984 is sustainable either. Its too rigid to withstand external events. BNW on the other hand, has tacot consent of all involved and is self reinforcing.
Both are similar in premise: the proletariat is distracted and kept down by something. Think of the sort of content that is produced in 1984; in Brave New World it is simply drugs instead. It makes you wonder about the spread of video games, instantly accessible entertainment, increased drug use, etc.
