Without a self-will and without that determination to eliminate such feelings, it's not a need it's a bad desire that you don't need to fill each time that you think that you need to gamble.
For me it all starts there, willpower is the only thing that can make the difference, there is no other way, the help is there and it can be given, but if the person does not do their part nothing will be achieved, nowadays things are much more open, the information is there and well social networks help people distort their objectives, when there is someone with addiction you have to consider taking care of them in the smallest way because it does affect them.
Gambling addiction can start with greed, chasing loses, being overconfident to continue gambling when you're winning. But it can develop if the gambler doesn't have self control, if a gambler don't know when to stop it becomes a very big problem. The gambler can keep on degenerating and keep getting worse, at that time they need external help to support them to get through it. People should be sensitive about the attitude of their loved ones, if they find out that one of their own is addicted to gambling they shouldn't condemn the person but show love and support and they can seek professional help if possible.
Though there are different approaches in terms of how to treat a person with gambling addiction problem but like what you said giving him support that he can treat himself by having that own will, that kind of mental support will gave a gambler a boost to keep trying, as aside from physical and those things that can only be provided by professionals, that moral support will be the best one that will lead him to change his thinking and start to work it on it's own to treat his gambling issues.