I am still wondering, what could possibly lead a person back to gambling after successfully quitting initially? Know well the reason for initially quitting was addiction, does it make sense to go back to gambling and become even more addicted?
First of all it is needed to figure out why originally a person became addicted to gambling. Because of desire to get more money, endless process of trying to win back what were lost, or a person loves to gamble in general. A person can return after quitting for various reason. I would name improvement in self control as a first one. If a person has learned how to stop himself from doing something he dives completely, then I see no problem to return.
It is also important for everyone who feel he's addicted to gambling to firstly accept that they are truly gambling addicts, then they can now proceed to the second stage which is the stage of identifying what exactly was the cause of the addiction.
It depends how long and how sharp, some people might not immediately remember this factor but will at least have a clue of the cause. Then once the person does that, he should then try as much as possible to figure out the cues to why he goes back to gambling anytime he feels like quitting. If he's able to put together everything it will be a lot easier for the person to plan strongly for a total exit out of such practice.