Good wives/husbands do not allow a family to break up because of any addictions of one family member. Such problems need to be solved together because a gambling addict is not able to cope alone. If the family is falling apart then it is likely that there are more serious problems within the family than gambling addiction.
This kind of awareness should be applied by everyone, not stay away from an addicted family member. but problems like this are sometimes inversely proportional and people who become addicted will feel isolated and even shunned by other family members.
and what happens is that it is true that it will be very difficult for the addict to change his attitude and even more so when this (shunned family) happens.
at least a moral approach and motivational advice will be more useful than rejection