Some More Studies on the Addictive Potential of Smoking

Reading through the literature on how normal cigarettes cause addiction, I came across something of potentially great importance to researchers on the addictive potential of e-cigs. This is the evidence available that strongly suggests that normal cigarettes are not only addictive because of their nicotine, but also because of some other components they contain.

The possibility of getting people who never previously smoked hooked on nicotine, is considered a theoretical reason to ban and regulate e-cigs, and to regulate them like tobacco or medicinal products.

And this of course is based on the assumption that the whole addictive potential can be reduced down to nicotine, and therefore that products like e-cigs could create a worrisome increase in those addicted to nicotine, and maybe even later encourage actual smoking.

But there are huge problems with this assumption. Aside from the fact that there is little evidence of people starting on e-cigs who were previously not smokers, and what there is says its a very small fraction of the total, the argument omits something that seems to be important: tobacco addiction is not thought to be all down to the nicotine, but also other compounds in cigarettes appear to increase the addictive potential of the nicotine, perhaps even greatly.

One aspect that may make ordinary cigarettes more addictive is believed to be the presence of substances that are MAO inhibitors. Cigarettes have a notable MAO inhibiting effect, and it turns out that this effect, which does not come from the nicotine but other components, has (at least in animals) a strong impact on the addictiveness that results from smoking.

See J Neurosci. 2005 Sep 21;25(38):8593-600.
Monoamine oxidase inhibition dramatically increases the motivation to self-administer nicotine in rats.

You can see the full paper here

And,

Monoamine oxidase A knockout mice exhibit impaired nicotine preference but normal responses to novel stimuli

There are not known to be MAO altering effects of nicotine replacement therapies and e-cigarettes. Therefore, it seems (at this stage) that e-cigs and Nicotine Replacement Therapy are inherently less addictive than tobacco. This should be another aspect for Health Authorities to look into when they appraise these options.