I had wondered if even Lureen drank a lot. Not as much as Jack, perhaps... But she certainly smoked a lot. If Jack became increasingly alcoholic, one would think that there would have been no dearth of alcoholic beverages in the house...
Jack never seemed to have become violent or abusive to Lureen. This is quite telling. Of course, one does not have to be violently drunk to be an alcoholic, and yet it would seem that the most we can accuse him (and her!) is to develop an indifference as far as the marriage waqs concerned.