By the "problem" of demand I mean that I wonder about the basic reality here. Why do human beings need to intoxicate themselves. Obviously, this has been done by a fairly large segment of the population since the first time Ooog found those pretty mushrooms or that that jar of fruit in the back of the cave had become rather tasty...
Naturally, not everyone "abuses" drugs in that they become addicted; though some drugs are so very addictive that they can become problematic to a very large percentage of folks that try them...(Crack and meth....Among others).
Still...Is it just part and parcel of the human condition that intoxication is attractive? Is depression more widespread among humans than is normally thought to be the case, and are people merely self-medicating. (some public-health authorities think this may be the case)
People only ask this question if they have never had a profound hallucinogenic experience.
The question is no more insightful than "why do we listen to music?" or "why do we play games?" or "why do we debate subjects on internet forums?".