nope. it's not because he's addicted, it's because he has mental problems. He ATTACKED his mom, how often do you ever hear of something like that happening just from marijuana (besides in reefer madness)? He obviously had some sort of pre-disposition that caused this behavior, perhaps some sort of dementia.
How awful, imagine being that mother, fuckin kid. Well, if he had any brothers or sisters, at least they won't have to worry about mom finding their stash.