As far as I know there are very few people who become addicted to gambling and share it with their family or others. What we typically see is that no gambler shares their addiction. They try to keep it secret as much as they can. A gambler will surely get a good solution when he shares this matter. Hiding only increases the problem so it is very important to share with others as much as possible. In some cases, it takes a long time for gamblers to identify the problem, so it is not possible to bring them back in time.
And the worst part is that gambling addiction itself can be very easy to hide, unless you were taking a look at the financial statements of the addicted gambler you will have no way to know that they are going through some financial problems.
While when it comes to other addictions it is very easy to tell at the early stages that there could be something going on that you are not being told, and this aggravates gambling addiction to the point that when those people finally ask for help the consequences of their addiction are too severe and it will be difficult for them to ever make a full recovery.