Talking about professional gamblers. It is already a person who knows their responsibility and risk. They become professionals because they can handle themselves more than others. So I would say there is no issue with them and nothing to worry about with these people because they know what the right thing to do is. We just assume the wrong thing.
Of course, they are rich gamblers who are not afraid to lose money.
Is that how you define someone that says they are a professional gambler? First, I think a professional gambler should be very rich because they must have to be winning consistently since they are pro. Also, apart from winning consistently, it's not every gambler claiming to be professional that really has the characteristics of handling themselves properly, some of them face the challenges that have been listed on the OP. There was this professional gambler in history, I can't remember his name but it was posted here some months ago, they said the guy developed mental problem and died. Being a pro in gambling is not easy and I don't know any professional in my place yet.