Of course, the relapses are stronger, I don't think you can decipher what led him to that state since it could be a mix of multiple situations such as debts or economic problems, but what is certain is that he closed the subject because he is ashamed and does not feel like exposing his vulnerabilities, maybe it is not just a gambling addiction, maybe it is something else, so the most recommended thing is not to pressure him, and let him open up when he wants or solve his things by himself.