Almost everything else in this game has a trade off
Huh, what ya mean? As Avv stated:
But why have long term negative effect? The negative effect is that they need to be farmed. Who cares that they are drugs and drugs are bad mkkay and so on. They are just gear in the end. Wearing a combat armor doesn't give any negative effects either.
I'm completely open to suggestions, I just don't like the idea of only benefits, and no drawbacks whatsoever.
There is still the addiction malus if you can't get high, and the price of using it.
And to have played with a system like you're describing, I think everyone else who played it have the same opinion: 10min fight, and then relog because your char is useless for next 10 min is not an interesting gameplay feature. Having malus when addicted because you don't have drugs is normal, but not being able to get rid of the malus even with the drug is bad.
I think drugs should be a pure benefit (aside from addiction), but to open possibilities, only be able to take one hard drug at a time.
Or maybe another system: you can only take up to 2 hard drugs at the same time. If you take one, you get only bonus. If you take two, you get a greater bonus, but a malus appear too!
For example: jet: +2AP, Psycho: +20%DR, jet+psycho:+2AP +15%DR -4PE