It is evident that decaffeinated coffee still contains a very low amount of caffeine.
What I'm interested in is that if decaf coffee still contains some very low amounts of caffeine, and caffeine is addictive, therefore: is decaf coffee addictive?
Since decaf coffee isn't the same as caffeine-free coffee, the key point regarding addiction is the amount of daily servings of decaf coffee that deliver the 100 milligrams of caffeine needed to acquire some sort of dependence 1.
The amount of such cups of decaf will vary according to the brand chosen. According to a study published in the Journal of Analytical Toxicology, and cited in the article Decaf coffee isn't caffeine free, they say that in average, a cup of decaf can hold about one-twentieth of the caffeine you get in a normal drip brewed coffee.
In that same article, they state that drinking more cups of decaf can compensate the lack of caffeine, and still be able to produce addiction.
So, it is indeed a matter of how many cups of decaf you drink.
Another take on addictiveness of coffee in addition to caffeine: there are several other psychoactive chemicals in coffee; some links/references are available from this page and this page. These chemicals include, for example, theanine, theobromine, and theophylline, in various amounts.
I can't find good sources to say if (or the extent to which) these or other psychoactive drugs in coffee are addictive as such. But, for example, theobromine is also present in chocolate; it has been suggested as a factor that contributes to "chocolate addiction" (citation listed at Wikipedia).
Standard disclaimers: this isn't medical advice; I am not a doctor; seek actual medical advice if you have questions.
My experience, as someone who went from drinking 2-4 cups of normal coffee plus several black teas per day to drinking 1-2 cups of decaf (and no tea) is that it IS addictive.
hoc_age's answer that there are psychoactive chemicals in coffee other than caffeine makes sense to me. The decaf I drink is the Swiss method of decaf which is supposed to remove more caffeine than other methods.
Yet if I don't have my decaf in the morning I crave it - with the exact same feeling as when I would "need" my normal caffeinated morning coffee.
I've tried drinking Caro and other similarly flavoured hot drinks but my body still wants coffee, decaf or not.
It definitely feels like there is something other than caffeine that makes it addictive.
This is not withstanding that caffeine itself is addictive; there is much science behind that to be in no doubt. I had the worst withdrawal symptoms when I quit normal coffee that no amount of decaf helped with. I felt physically sick and had crushing headaches that lasted a week and got worse every day until they finally disappeared.
I definitely get a caffeine withdrawal headache when I stop drinking decaf coffee for a couple days. A decade ago I was a regular coffee drinker, but the addiction and need for regular caffeine infusion didn't fit well with motherhood's scheduling and I had to stop. I did completely cut out all coffee/tea/soda sources of caffeine and, after I re-adjusted, life was better. Now when I drink, accidentally, 3 or more days (8-16oz/day) of instant decaf coffee in a row and then skip a 4th day....an, albeit milder, old caffeine withdrawal headache makes me notice I've missed out. The only other sources of caffeine in my diet are a minimal bit of chocolate.
