it doesn't give you the euphoric feeling that hydros or percs do.

well...without getting into alot of unsolicited pharmacology details...it binds to the exact same receptors that the other drugs do...and does so with high affinity...binds them strongly. This coupled with a very long half life, makes it quite addictive and difficult to get off of. Having never taken this drug personally, I can't speak to the euphoric effects or lack there-of, but that apparently isn't a pre-requisite for a drug being addictive if sufficient exposure to it occurs. Not sure if this helps or not.

From a more psychological perspective...I could get addicted to a breath mint if it stuck to the mu receptor :)

oh...and there are also very important differences between physical dependence and addiction, but in my screwed up brain, those don't occur independently. Others might have a differnt view.