[ivanca]

The relationships between actions are so complex that "global utility" is just as blurry, maybe the ones overdosing are mostly criminals; maybe the company that creates the chemical products for the distilling process of the heavy drugs is actually owned by some guy that is going to find the cure for cancer thanks to the funds earned from his chemical company. Or maybe experiencing reality is not better than your experience on drugs. Yeah, those are very controversial statements but is mostly because it falls under the field of psychology, sociology and philosophy, which arguably are even more blurry.

[darkmighty]

Well, the definition itself isn't blurry I'd say, since it's pretty much universal: the examples you cited should be encompassed as possibilities by the model. It's just hard to define because it involves the complexities and oddities of morality, happiness and the like -- our objective knowledge of those is so restricted and sparse that we're better off just "winging" judgements from our legacy of humanities study.