People who are dependent on gambling to alter their mood are what we called gambling addict. We can spot them by compairing their mood when they are gambling and when they are not gambling. We can also look at how they assess themselves when they are gambling. Most gambling addict does not care about time, responsibilities and even ignoring their job when they are playing. They even go anywhere when there is a gambling game.
Yes, addicted people are always the same. Principally by the irresponsibility. Usually these people don't have rules on their lifes, they just can live well when others are taking care of them, but if they live by themselves probably they will ruin everything to feed their addiction, in this case the game. They can start betting all their saved money, and when it finishes, they can stop eating to have more money to gamble.
In the end they can start selling stuff from their houses to gamble until they have nothing more and become hobos, worse is when the gambling addiction comes with another addictions like the drugs and alcohol.
Well, I disagree with you, because they are not all irresponsible or selling their properties like their houses and other stuffs, maybe just some of them, but not all of them. Gambling addicts is really hard to find, because they are spending most of their time in their rooms, playing on online casinos, and if you are going to find a real one in an actual casinos, then maybe you will able to find one.
But how can we say that someone is an addict in gambling? by the way he talks? I don't think so, maybe we could know it by his approach on gambling, just like what you have said, selling their properties, but why do they sell it? it's simple, because they are always recklessly betting their money, resulting them to an empty pocket, that is why they don't have a choice but to make a way for their addiction to continue, and that is why they ended up selling their properties and other stuff.