Celebrim
Legend
Related question.
Player creates a really low wisdom character who generally only thinks for himself, drinks too much, etc etc.
Would you consider the occasional wisdom save for said character to avoid getting drunk during his turn on watch? Or something else equally stupid like falling asleep or wandering out of camp when he hears a strange but harmless sounding noise.
No, having low wisdom means you have low perception which already covers your inability to concentrate when on the watch. However, once you've established that the perception check is failed, you or the player may be free to color the failure as being explained by the players poor habits. Personally, I'd leave that job to the player, though some groups allow the GM's to narrate failures.
Addiction and other things like that should be treated as color unless they are established mechanically by some process of play. For example in some games you might be able to take 'addiction (alcohol)' as a flaw, but generally if you do so, you are allowed to receive a corresponding advantage in fair exchange. If 'addiction (alcohol)' is a well defined status in your game, then perhaps some process of play might inflict addictions on players, just as others might inflict curses or handicaps. However, if you are asking questions like this, chances are you don't have mechanical support for ideas like that, so my advice is to keep them at the level of quirks and use them to color the RP only, and not influence success or failure beyond what is already established by having a low Wisdom.