A person who knows how to control his own emotion will make him feel crazy when he is losing a big money as he plays and that is going to be a big deal even he is a good in controlling himself. And if someone is not really helping himself to stay away from gambling and doesn't do anything then that will be also a factor that can make him a gambling slave.
True, it is also depend of a willingness of an addicted person if they really wanted to stay away in gambling, because for me once you don't have willingness your plan to stay away will always be useless. We also need the help of the advice of other people so that we can hear their sides on how to really stop playing gambling.