If he denies there is a problem and he refuses to listen, then nothing can be done at this point in terms of the gambler.
The family, however, can choose not to stick around with the gambler out of fear, embarrassment or what have you. Having his family leave him might be the trigger which gets him to realize that there is an issue. And if it isn’t, well, at least they are doing the best for them.
It all depends on who you are dealing with here. If it is the gambler, you have your work cut out for you, you need to get them to realize that they have an issue and this is not a way to function.
If you are friends with his wife, get her to realize that SHE recognizes the problem, and sticking with him is, in essence, supporting the addiction. Get her to realize that she wont want her credit ruined nor does she want people barging into their home (in front of their kids) to collect money for shady people the gambler did his gambling with.
If you are this woman, you need to do what is best for you and your kids. And I think you know what that is.
Gambling is an addiction, much like drugs and alcohol. And like drugs and alcohol, one is never “cured”. One is always “recovering”. One drink is poisonous to an alcoholic, as is one bet by a gambler.
The issue with gambling, however, is that it is easier to hide. One can easily log on to gambling websites and place credit card bets without people realizing until it is too late.