how to tell a cocaine addict, how to help

[actarus]

some of swim's friends have been using blow on a regular weekly basis for years now, roughly once per week.
nobody of them has ever thought to be addicted, its a kinda taboo argument.
they just lock inside someone's place and keep snortin that shit all night long. (What's the fuckin point?)
can someone who has been using it for 5-6 years (who less who more) on a regular weekly basis be called an addict, although all of them live regular lifes (good jobs, normal social life, etc etc)?