I have one idea for the practical use of smoking weed ingame, and using other drugs too.
The idea is to add value to an artistic craft after having smoked the weed for being high. Like, you get the weed however you wish. Then, when you smoke it and for example make a painting, as long as the crafting is done within the duration of the high, the painting gains a tag that says the creator was high on such n such drug, which in turn adds either a small amount of actual game dynamic value to the original and the painting's prints, along with the social value for having created something artistic while being on whatever drug.
This can apply to all drugs and give all artistic creations some game dynamic value to whatever crafted item or musical composition, etc.
What do you guys think? Please comment and suggestions.