People with gambling addiction should have a financial barrier. They should have as little money as possible or better still don't go out with any money. What I mean is that someone else should be in possession of their money in their bank account. This someone could be a spouse, a significant other, a parent. Or better still if you are married, open a joint bank account with your spouse and have her on charge of it. She'll get notifications whenever any withdrawal is made. If you are single then talk to your bank about your situation so that they don't loan you money when you don't need it.
There are some isssues attached with that, some people do not like their spouse to be attacked more to their financial life and they just want to be in control of their money themselves, just like me and I believe just like other men. It may be the best to do but many will not do that a long as they are living and not psychotic. Gambling addiction can be very hard to treat but it can start by letting your spouse know about it but not to the extent you will give all your financial income to her to be in control. There should be other ways that can help.