Shrooms ain't addictive either.
Addiction should be roleplayed not forced upon. Otherwise, chea, "RPG" not RP as people have said.
I've seen addiction scripted on other servers and it just meant that people will not use drugs (like, at all).
Also.. there are no plus sides to drugs IRL (except like self-discovery/meditation and all that stuff. Also don't get me started on medical marijuana, that's a whole another story)
Source: Personal experience
-1
Drugs are currently useless ingame, the point of this suggestion is to give them some type of advantage (even though they're gonna have more disadvantages). Noone will roleplay addiction after taking 10 Meths and 8 Heroins, and we can't force them to RP it as we can't monitor a player 24/7 incase they take some drugs. This script would basically be the "Do's & Dont's" of drugs. People will stay away from hardcore drugs, unless they choose not to and they will be faced with consequences/down-sides after taking it aswell.