Effects of electronic cigarette e-liquid flavouring on cigarette craving

BackgroundE-liquid flavour restrictions may discourage electronic cigarette (e-cigarette) uptake among youth. However, possible unintended consequences may include reduced appeal and effectiveness of e-cigarettes for smoking cessation. Non-tobacco flavours appear to be important for smoking cessation, but how and why are currently unclear.MethodsWe conducted an experimental study in a UK sample of adult daily smokers using an independent groups design (N=84). Participants were randomised to use an e-cigarette with nicotine-containing fruit/sweet-flavoured e-liquid (blackcurrant, strawberry, vanilla, caramel) or unflavoured e-liquid for 1 week. The primary outcomes were average, peak and cue-elicited cigarette craving (the latter was assessed using a cue exposure task). The secondary outcomes were smoking lapse occurrence, enjoyment of the e-cigarette, ease of transitioning from smoking to using an e-cigarette, intentions to continue using an e-cigarette, intentions and motivation to quit smoking, return to smoking, and continuation of e-cigarette use.ResultsE-liquid flavouring did not appear to have an effect on average cigarette craving (b 0.18, 95% CI −0.44 to 0.79, p=0.57), peak cigarette craving (b −0.12, 95% CI −0.59 to 0.35, p=0.62) or cue-elicited cigarette craving (b −0.21, 95% CI −3.86 to 3.43, p=0.91). We did not find evidence of a difference in secondary outcomes.ConclusionsWe did not find evidence to suggest that nicotine-containing fruit/sweet-flavoured and unflavoured e-liquids have different effects on cigarette cravings after 1 week of use. Further research is needed to establish if differences emerge over longer periods of exposure and extend to smoking cessation outcomes.

Segregation of default mode from frontoparietal system protects against smoking lapse

Quitting smoking is notoriously difficult. Models of nicotine dependence posit that deficits in cognitive control contribute to failures to maintain smoking abstinence during smoking cessation attempts. We examine the role for large-scale functional brain systems associated with cognitive control in smoking lapse. We use data from 70, five-minute functional magnetic resonance imaging (fMRI) scans in 17 daily smokers (5 female) undergoing a smoking lapse paradigm after 12 hours of smoking abstinence. Cox regression results indicate that decreased segregation of the default mode system from the frontoparietal system undermine the ability to resist smoking. Results lend support to the hypothesis that large-scale functional brain systems associated with cognitive control are implicated in smoking lapse behavior and point to the importance of cognitive control as a mechanism underlying smoking relapse.