My advice to such gamblers is that they should always be aware of knowing when to stop, being aggressive when winning or loosing doesn't really help any issues it just worsens it. I'm a responsible gambler that isn't aggressive over wins nor losses.
They are in the momentum whenever they become aggressive and that's the reason why they seem to be in that state because they can't lose that moment. And if that moment losses, they'll have a problem into it and having the same regret of losing money and losing that very moment that they have been waiting for. But I am with you that they shouldn't be like that because they're going to make things worse instead of fine and controlled. They have control over themselves but they will have to have a hard time in dealing with it later on when they're in that situation where they think they're fine but if someone is asked to look after them, they'd probably say no.