Rich people gamble for entertainment mostly, Poor people try to gamble so they can earn some income or become rich. That's where the difference is. And to be honest, if you want to avoid depression and even addiction, look at gambling as a way of entertaining yourself, and you should do it daily. It should be something occasional.
But at the same time, the losses of poor people can be quite insignificant, because they gamble with very small amounts of money that are left after all their essential payments. A rich person can afford to gamble with much larger sums, and as a result, they can much more easily and quickly lose large amounts of money and suffer huge losses, which can lead to a faster development of addiction due to the desire to win back what was lost.