Smokers seeing ecigs being used makes them want to smoke (cigarettes)

On May 21, 2014 Andrea King and colleagues published a nice experimental study, "Passive exposure to electronic cigarette (e-cigarette) use increases desire for combustible and e-cigarettes in young adult smokers," in Tobacco Control, showing that when young adult smokers saw someone using an e-cigarette it made them want to smoke as much as if they saw someone smoking a cigarette.  (The "passive exposure" is watching someone use an ecig during a conversation.)
 
Seeing an ecigarette being used did not make smokers who did not already use ecigarettes want to use an ecigarette, but did stimulate desire for an ecigarette among ecigarette users.  Exposure to to a neutral stimulus (seeing someone drink a bottle of water) did not affect desire for either a cigarette or ecigarette.
 
This result is consistent with an earlier study,"Adult smokers’ receptivity to a television advert for electronic nicotine delivery systems," that Annice Kim and colleagues  published in Tobacco Control (in October 2013), that found that watching an ad for Blu ecigs that stressed that they can be used anywhere elicited an ureg to smoke and thoughts about smoking cigarettes as well as thoughts about quitting.  People who used ecigs were significantly more likely than non-users to report thinking about smoking cigarettes after seeing the Blu ad.  (Lorillard Tobacco sells Blu, so they win either way.)
 
These papers contribute to our understanding about why people who use ecigarettes are less likely to quit smoking (even if ecigarettes are helpful for those using them to make a quit attempt).
 
Another interesting paper just published in Nicotine and Tobacco Research by William Lechner and colleagues in Oklahoma of people recruited in vape shops, "Effects of Duration of Electronic Cigarette Use."  This cross-sectional study showed that the longer that they had been using e-cigarettes the fewer cigarettes they were smoking.  They also found some evidence that nicotine dependence in ecigarette users dropped among people who were heavy cigarette smokers but increased among people who were light smokers.  (The authors raise the possibilty that people using tank systems at vape shops may behave differently than people who use other kinds of ecigarettes.)