Long term gambling does not always mean addiction. Addiction should not be depending on how long you have been involved but it depends on how are you deal with it. I've been involved in gambling more than 10 years, indeed I have to admit that I was addicted to it on my first year as I could not control myself. But after that I could manage/control myself, I know when to start and when to stop so I do not think it is an addiction as it was.
Off course doesn't mean as addiction
Such example as myself, i play more because i know i can profit even more and i have fun with it. But isn't an addiction because i have my own schedule / time when i want to leave Casino area and return during my week time.