The character speaking to him has to have high Int and Cha scores. Then there should be a dialogue option that tells him he drinks to compensate for his lost aspirations or opprtunities or some such, and that he doesn't need the bottle.
(sorry it's been a while since I played the game)
__________________ GameBanshee Make your gaming scream! "I have seen them/I have watched them all fall/I have been them/I have watched myself crawl" "I will only complicate you/Trust in me and fall as well" "Quiet time...no more whine" | 
Drunk fisher 
Linear Mode
