If a gambler already shows weird actions everytime he can't go gambling session then that might already be a sign of being addicted. Some gamblers also lose the ability to control their self betting even they almost lose everything they have. This kind of gambler need outside environment assistance or a sort of rehabilitation.
This can be one of quality of the gambler that he seems to be retarded and weird all the time and the reasons for his retardation are simple; he just becomes frightened after losing bigger amounts in gambling, thats why he remains sad and uncomfortable and doesnt communicate with other people like normal people do. Also the gambler can be identified that he is an addict by noticing his routine, he will remain busy all the time and calculating things in mind.