Is Addiction Itself Problematic?

I had lunch yesterday with my editors from Johns Hopkins University Press and one of them who ordered a cup of coffee was making light of her supposed caffeine addiction.  It leads to the question whether such an addiction would be a problem.  Suppose you are a fully functioning addict -- addicted to whatever it is -- and the addiction does not harm your ability to have the life you want and does not cause hardship to those you care about.  Maybe you really enjoy the object of your addiction.  Is this a problem?  Addiction, by its nature is a forfeiting of autonomy.  Doesn't an addiction, in this way, make you less human?  But if your life is no worse, is it problematic?  Is it addiction or the effects of many addictions that are problematic?