I, for one, would prefer if we stopped calling ourselves "nicotine addicts," and I certainly don't agree that I suffer from a genetic personality flaw that kept me smoking. There are enough people calling smokers derogatory names without us vapers joining in the chorus.
HERE is an excellent 3-part article by Carl Phillips on the topic of "addiction," which he says has no clearly established scientific or medical definition.
And please don't be so quick to believe that nicotine alone is addictive. There is mounting scientific evidence that nicotine is no more addictive than caffeine. If it's so addictive, where are all the nicotine gum addicts, nicotine patch addicts, nicotine lozenge addicts?
If nicotine were as addictive as some claim, then vapers would be using higher and higher concentrations of it in their e-liquid. In actual fact, the opposite is typically the case. I went, in stages, from 36mg/ml to 3 mg. This is the way it typically works with a majority of vapers and many are at 0.0mg.
There have been numerous studies involving lab animals trying to get them to show a dependence response to nicotine, similar to the response to ......., etc. Researchers have found that nicotine doesn't produce that kind of response. The animals are "meh" when it comes to nicotine.
Drugs such as ......., barbiturates, and ...... are considered addictive (a somewhat better term would be "dependence inducing") based on their ability to intoxicate, cause social damage, and produce dramatic physical withdrawal syndromes. The nicotine in e-cigarettes has none of those effects.
With these other substances, in the initial stages of use more and more of the product is required to produce the same effect, i.e., “tolerance”; it is “reinforcing,” meaning that it is sufficiently rewarding to spur self-administration; and abrupt cessation can lead to powerful craving and a recognizable withdrawal syndrome. This doesn't seem to be the case with nicotine when it's not paired with the other substances in tobacco.
Tobacco companies learned long ago that the introduction of certain chemicals enhanced the psychological and physical effects of smoking. There are roughly 600 additives approved for use in cigarettes, including a number of pyrazines which have effects on the human body and brain which are still erroneously attributed to nicotine. It's now been shown that monoamine oxidase inhibitors (MAOIs) greatly enhance the dependence-creating properties of nicotine. These are present in cigarettes but not in the extracted nicotine used in patches, gum and e-cigarettes. Additionally, a number of tobacco alkaloids such as anatabine, cotinine myosmine, acetalehyde and nitric oxide work in similar fashion.
E-cigarettes have very little appeal to non-smokers because their brains aren't conditioned to want, need or use nicotine, so it has little significant effect on them.
ETA: This forum doesn't allow references to certain controlled narcotics. Thus the "......."