[chrisser]

Perhaps most surprising is that, in studies by Boyd and others, nicotine has not caused addiction or withdrawal when used to treat disease. These findings fly in the face of nicotine’s reputation as one of the most addictive substances known, but it’s a reputation built on myth.

As a former smoker, former by switching to e-cigarettes, I find this not to be the case entirely.

Perhaps e-cigs aren't pure nicotine, but there is a definite withdrawal issue with them. It's not as bad as tobacco, but it's still there.

Several times I've run out of e-cig juice and fallen back onto analogs because of the withdrawal cravings.

[jjsheridan5]

Correlation doesn't imply causation. I, too, have observed this. There are a couple of possibilities: one is that once you have become addicted to the cocktail of chemicals in tobacco, there is some change in the brain that makes us susceptible to addiction of nicotine (in other words, for a non-smoker, nicotine is not addictive, but for a life-long smoker, it is). The more likely explanation is this, in my opinion: nicotine has a number of positive benefits. When you stop smoking (which you are addicted to), you are struggling with "withdrawal". Nicotine's positive benefits make that withdrawal tolerable. So when you remove nicotine, it isn't that you are suffering from withdrawal from nicotine: rather, it is that the chemical which was helping you deal with withdrawal is now absent, and you are now fully exposed to the underlying addiction.

This dovetails with other studies that show that tobacco (and presumably nicotine), are highly beneficial for people dealing with any addiction. So much so, that it used to be conventional wisdom to provide drug addicts with tobacco to help them deal with cessation.